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Search for Higgs and Z boson decays to Jψγ and Υ(nS)γ with the ATLAS detector

Aad, G.; et al., [Unknown]; Aben, R.; Angelozzi, I.; Beemster, L.J.; Bentvelsen, S.; Berge, D.; Bobbink, G.J.; Bos, K.; Brenner, L.; Butti, P.; Castelli, A.; Colijn, A.P.; de Jong, P.; de Nooij, L.; Deigaard, I.; Deluca, C.; Dhaliwal, S.; Ferrari, P.; Gadatsch, S.; Geerts, D.A.A.; Hartjes, F.; Hessey, N.P.; Hod, N.; Igonkina, O.; Karastathis, N.; Kluit, P.; Koffeman, E.; Linde, F.; Mahlstedt, J.; Mechnich, J.; Meyer, J.; Oussoren, K.P.; Sabato, G.; Salek, D.; Slawinska, M.; Valencic, N.; van den Wollenberg, W.; van der Deijl, P.C.; van der Geer, R.; van der Graaf, H.; van der Leeuw, R.; van Vulpen, I.; Verkerke, W.; Vermeulen, J.C.; Vreeswijk, M.; Weits, H.; Williams, S. Published in: Physical Review Letters

DOI: 10.1103/PhysRevLett.114.121801

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Citation for published version (APA): Aad, G., et al., U., Aben, R., Angelozzi, I., Beemster, L. J., Bentvelsen, S., Berge, D., Bobbink, G. J., Bos, K., Brenner, L., Butti, P., Castelli, A., Colijn, A. P., de Jong, P., de Nooij, L., Deigaard, I., Deluca, C., Dhaliwal, S., Ferrari, P., ... Williams, S. (2015). Search for Higgs and Z boson decays to Jψγ and Υ(nS)γ with the ATLAS detector. Physical Review Letters, 114(12), [121801]. https://doi.org/10.1103/PhysRevLett.114.121801

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Search for Higgs and Z Boson Decays to J=ψγ and ϒðnSÞγ with the ATLAS Detector G. Aad et al.* (ATLAS Collaboration) (Received 15 January 2015; published 26 March 2015) A search for the decays of the Higgs and Z bosons to J=ψγ and ϒðnSÞγ (n ¼ 1; 2; 3) is performed with pp 20 3 −1 pffiffiffi collision data samples corresponding to integrated luminosities of up to . fb collected at s ¼ 8 TeV with the ATLAS detector at the CERN Large Hadron Collider. No significant excess of events is observed above expected backgrounds and 95% C.L. upper limits are placed on the branching fractions. In the J=ψγ final state the limits are 1.5 × 10−3 and 2.6 × 10−6 for the Higgs and Z boson decays, respectively, while in the ϒð1S; 2S; 3SÞγ final states the limits are ð1.3; 1.9; 1.3Þ × 10−3 and ð3.4; 6.5; 5.4Þ × 10−6, respectively.

DOI: 10.1103/PhysRevLett.114.121801 PACS numbers: 14.80.Bn, 13.38.Dg, 14.70.Hp, 14.80.Ec

Rare decays of the recently discovered Higgs boson [1,2] important benchmark for the search and eventual observa- to a quarkonium state and a photon may offer unique tion of H → Qγ decays. Additionally, experimental access sensitivity to both the magnitude and sign of the Yukawa to resonant Qγ decay modes would also provide an couplings of the Higgs boson to quarks [3–6]. These invaluable tool for the more challenging measurement of couplings are challenging to access in hadron colliders inclusive associated Qγ production, which has been sug- through the direct H → qq¯ decays, owing to the over- gested as a promising probe of the nature of quarkonium whelming QCD background [7]. production in hadronic collisions [15,16]. Among the channels proposed as probes of the light The decays Z → Qγ have not yet been observed, with quark Yukawa couplings [4,6], those with the heavy the only experimental information arising from inclusive J=ψ ϒðnSÞ n ¼ 1; 2; 3 BðZ → J=ψXÞ¼ð3 51þ0.23Þ 10−3 quarkonia or ( ), collectively measurements, such as . −0.25 × denoted as Q, in the final state are the most readily and the 95% confidence level (C.L.) upper limits accessible, without requirements for dedicated triggers B½Z → ϒðnSÞX < ð4.4; 13.9; 9.4Þ × 10−5, from LEP and reconstruction methods beyond those used for identi- experiments [17–21]. fying the J=ψ or ϒ. In particular, the decay H → J=ψγ may This Letter presents a search for decays of the recently represent a viable probe of the Hcc¯ coupling [4], which is observed Higgs boson and the Z boson to J=ψγ and ϒðnSÞγ sensitive to physics beyond the Standard Model (SM) [8,9], final states. The decays J=ψ → μþμ− and ϒðnSÞ → μþμ− at the Large Hadron Collider (LHC). The expected SM are used to reconstruct the quarkonium states. The search is branching fractions for these decays have been calculated performed with a sample of pp collision data correspond- to be BðH→J=ψγÞ¼ð2.80.2Þ×10−6, B½H→ϒðnSÞγ¼ ing to an integrated luminosity of 19.2 fb−1 (20.3 fb−1) for ð6 1þ17.4;2 0þ1.9;2 4þ1.8Þ 10−10 J=ψγ ½ϒðnSÞγ . −6.1 . −1.3 . −1.3 × [5]. No experimental the analysis,pffiffiffi respectively, recorded at a information on these branching fractions exists. These center-of-mass energy s ¼ 8 TeV with the ATLAS decays are a source of background and potential control detector [22], described in detail in Ref. [23]. þ − sample for the nonresonant decays H → μ μ γ. These Higgs boson production is modeled using the POWHEG- nonresonant decays are sensitive to new physics [10]. BOX Monte Carlo (MC) event generator [24–28], separately Rare decay modes of the Z boson have attracted attention for the gluon fusion (ggF) and vector-boson fusion (VBF) focused on establishing their sensitivity to new physics processes calculated in quantum chromodynamics (QCD) α [11]. Several estimates of the SM branching fraction for the up to next-to-leading order in S. The Higgs boson trans- p decay Z → J=ψγ are available [12–14] with the most recent verse momentum ( T) distribution predicted for the ggF being ð9.96 1.86Þ × 10−8 [14]. Measuring these Z → Qγ process is reweighted to match the calculations of branching fractions, benefiting from the larger production Refs. [29,30], which include QCD corrections up to cross section relative to the Higgs case, would provide an next-to-next-to-leading order and QCD soft-gluon resum- mations up to next-to-next-to-leading logarithms. Quark mass effects in ggF production [31] are also accounted for. * Full author list given at the end of the article. Physics beyond the SM that modifies the charm coupling Published by the American Physical Society under the terms of can also change production dynamics and branching the Creative Commons Attribution 3.0 License. Further distri- fractions. In this analysis we assume the production rates bution of this work must maintain attribution to the author(s) and and dynamics for a SM Higgs boson with mH ¼ 125 GeV, the published articles title, journal citation, and DOI. obtained from Ref. [32], with an uncertainty on the

0031-9007=15=114(12)=121801(19) 121801-1 © 2015 CERN, for the ATLAS Collaboration week ending PRL 114, 121801 (2015) PHYSICAL REVIEW LETTERS 27 MARCH 2015 dominant ggF production mode of 12%. The VBF signal b-hadron decays, the measured transverse decay length model is appropriately scaled to account for the production Lxy between the dimuon vertex and the primary pp vertex W Z σ of a Higgs boson in association with a or boson or in is required to be less than three times its uncertainty Lxy.In association with a tt¯ pair, correcting for the relative this case, the primary pp vertexP is defined as the recon- production rates and experimental acceptances for structed vertex with the highest p2 of all associated H → i Ti these channels. Contributions from nonresonant tracks used to form the vertex. ðZ=γÞγ → μþμ−γ decays are expected to be negligible Photon reconstruction is seeded by clusters of energy – with respect to the present sensitivity [33 35]. in the electromagnetic calorimeter. Clusters without The POWHEG-BOX MC event generator is also used to matching tracks are classified as unconverted photon Z model boson production. The total cross section is candidates. Clusters matched to tracks consistent with estimated from Ref. [36], with an uncertainty of 4%. the hypothesis of a photon conversion into an eþe− pair Z The Higgs and boson decays are simulated as a are classified as converted photon candidates [44]. cascade of two-body decays. Effects of the helicity of Reconstructed photon candidates are required to have γ the quarkonium states on the dimuon kinematics are transverse momentum p > 36 GeV, pseudorapidity Z T accounted for in both cases. For Higgs and boson events jηγj < 2.37, excluding the barrel/endcap calorimeter tran- generated using POWHEG-BOX,PYTHIA8.1 [37,38] is used sition region 1.37 < jηγj < 1.52, and to satisfy the “tight” to simulate showering and hadronization while PHOTOS photon identification criteria [45]. To further suppress the [39,40] is used to provide QED radiative corrections to the contamination from jets, an isolation requirement is final state. The simulated events are passed through the full imposed. The sum of the transverse momentum of all GEANT4 simulation of the ATLAS detector [41,42] and tracks and calorimeter energy deposits within ΔR ¼ 0.2 of processed with the same software used to reconstruct data the photon direction, excluding those associated with the events. reconstructed photon, is required to be less than 8% of the J=ψγ The data used to perform the search in the channel photon’s transverse momentum. were collected using a trigger that required at least one Combinations of a Q → μþμ− candidate and a photon, p > 18 ϒðnSÞγ muon with T GeV. The events used in the satisfying Δϕðμþμ−; γÞ > 0.5, are retained for further channel were collected with a trigger requiring an isolated analysis. To improve the sensitivity of the search, the p > 24 p muon with T GeV and a dimuon trigger with T events are classified into four exclusive categories, based thresholds of 18 and 8 GeV for each of the muons, upon the pseudorapidity of the muons and the photon respectively. Events are retained for analysis if they were reconstruction classification. Events where both muons are collected under stable LHC beam conditions and the within the region jημj < 1.05 and the photon is (is not) detector components were operating normally. classified as a conversion constitute the “barrel converted” Muons are reconstructed from inner-detector tracks (BC) [“barrel unconverted” (BU)] category. Events where combined with independent muon spectrometer tracks or at least one of the muons is outside the region jημj < 1.05 pμ > 3 track segments [43] and are required to have T GeV and the photon is (is not) classified as a conversion jημj < 2 5 Q → μþμ− and pseudorapidity . . Candidate constitute the “endcap converted” (EC) [“endcap uncon- decays are reconstructed from pairs of oppositely charged verted” (EU)] category. The number of candidates observed muons consistent with originating from a common vertex. in each category following the complete event selection is p The highest- T muon in a pair, called the leading muon in shown in Table I. pμ > 20 the following, is required to have T GeV. Dimuons The total signal efficiency (kinematic acceptance, trig- m J=ψ with a mass, μμ, within 0.2 GeV of the mass [17] are ger, and reconstruction efficiencies) in the J=ψγ final state þ − identified as J=ψ → μ μ candidates. In case both muons is 22% and 12% for the Higgs and Z boson decays, μ in the pair are within jη j < 1.05, the said requirement is respectively. The corresponding efficiencies for the ϒðnSÞγ 8 0

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TABLE I. The number of observed events in each analysis category. For comparison, the expected background yield is given in parentheses for the two mμμγ ranges of interest. The Higgs and Z boson contributions expected for branching fraction values of 10−3 and 10−6, respectively, are also shown. For ϒðnSÞγ, the 1S; 2S, and 3S contributions are summed.

Observed (expected background) Signal Mass range [GeV] Z H Category All 80–100 115–135 B ½10−6 B ½10−3 J=ψγ BU 30 9 (8.9 1.3)5(5.0 0.9) 1.29 0.07 1.96 0.24 BC 29 8 (6.0 0.7)3(5.5 0.6) 0.63 0.03 1.06 0.13 EU 35 8 (8.7 1.0)10(5.8 0.8) 1.37 0.07 1.47 0.18 EC 23 6 (5.6 0.7)2(3.0 0.4) 0.99 0.05 0.93 0.12 ϒðnSÞγ BU 93 42 (39 6)16(12.9 2.0) 1.67 0.09 2.6 0.3 BC 71 32 (27.7 2.4)5(9.7 1.2) 0.79 0.04 1.45 0.18 EU 125 49 (47 6)16(17.8 2.4) 2.24 0.12 2.5 0.3 EC 85 31 (31 5)18(12.3 1.9) 1.55 0.08 1.60 0.20 inclusive QCD background shape, obtained with a data- the surviving pseudocandidates are used to construct driven approach, and of the Z → μþμ− background shape, templates for the kinematic distributions, notably the μμ obtained from simulation, is described in the following two inclusive QCD background mμμγ and pT distributions. paragraphs. The background from Z → μþμ−γ decays is modeled The background from inclusive QCD processes is with templates derived from a sample of simulated Z boson modeled with a nonparametric data-driven approach using events with mμμ in the ϒðnSÞ mass region. To validate this templates to describe the kinematic distributions. The background model with data, the sidebands of the mμμγ μþμ−γ approach exploits a sample of loosely selected distribution in several validation regions, defined by J=ψγ events, around 2400 in the channel and around relaxed kinematic or isolation requirements, are used to ϒðnSÞγ 3200 in the channel. These control samples are compare the prediction of the background model with the Qγ formed from events satisfying the nominal selection, data. Good agreement within the statistical uncertainties is but with relaxed dimuon and photon transverse momenta observed. pγ > 25 pμμ > 25 ( T GeV and T GeV) and isolation require- The composition of the inclusive QCD background and ments (separate fractional calorimeter energy and track the Z → μþμ−γ decay contribution is investigated with momentum isolation for the photon and dimuon system of data. The details of the composition do not enter directly less than 60%). Contamination of this sample from signal the background estimation for this search, but the compo- events is expected to be negligible. Probability density sition itself is a crucial input in feasibility studies for future pμμ pγ Δηðμþμ−; γÞ functions (pdfs) used to model the T , T, searches or measurements, where projections of these Δϕðμþμ−; γÞ and distributions of this control sample, backgrounds to different center-of-mass energies or lumi- independently for each category, are constructed using nosity conditions are needed. To facilitate this study, the Gaussian kernel density estimation [46]. To account for m jL =σ j γ þ − selection requirements on μμ and xy Lxy are relaxed to kinematic correlations, the distributions of pT, Δηðμ μ ; γÞ þ − include the sideband regions. In the J=ψγ final state, a and Δϕðμ μ ; γÞ are estimated in eight exclusive regions of μμ simultaneous unbinned maximum likelihood fit to the mμμ pT . In the case of the dimuon and photon isolation and jLxy=σL j distributions is performed. Once the simul- variables, correlations are accounted for by using two- xy dimensional histograms derived in five exclusive regions of taneous fit is performed, the composition of the subset of μμ m jL =σ j pT . The mμμ distributions are modeled using Gaussian events satisfying the nominal μμ and xy Lxy require- pdfs, with parameters derived from a fit to the control ments is estimated. After the complete event selection, sample. In the ϒðnSÞγ channel, the data control sample is around 56% of the events originate from prompt J=ψ corrected for contamination from Z → μþμ−γ decays. The production, 3% from nonprompt J=ψ production (from pdfs of these kinematic and isolation variables are sampled b-hadron decays) and 41% are combinatoric backgrounds to generate an ensemble of pseudocandidates, each with a from nonresonant dimuon events. complete Qγ four-vector and an associated pair of corre- A separate simultaneous fit to the mμμγ and mμμ lated dimuon and photon isolation values. The nominal distributions of the same sample of candidate J=ψ events selection requirements are imposed on the ensemble and finds no significant contribution from Z → μþμ−γ decays, a

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24 25 22 ATLAS ATLAS 20 s=8 TeV ∫Ldt = 19.2 fb-1 s=8 TeV ∫Ldt = 19.2 fb-1 20 18 Data Data S+B Fit S+B Fit 16 Background Background 14 H [B=10-3] 15 H [B=10-3] -6 -6 12 Z [B=10 ] Z [B=10 ] 10 10 8 Events / 4 GeV Events / 4 GeV 6 5 4 2 0 40 80 120 160 200 0 50 100 150 200 μμγ mμμγ [GeV] p [GeV] T

μμγ FIG. 1 (color online). The mμμγ and pT distributions of the selected J=ψγ candidates, along with the results of the unbinned maximum likelihood fit to the signal and background model (S þ B fit). The error bars on the data points correspond to the statistical uncertainties. The Higgs and Z boson contributions as expected for branching fraction values of 10−3 and 10−6, respectively, are also shown. conclusion that is also supported by a study based on The uncertainty in the shape of the inclusive QCD simulated Z → μþμ− events. background is estimated through the study of variations For the ϒðnSÞγ final state a simultaneous fit is performed in the background modeling procedure. The shape of the to the mμμγ and mμμ distributions. After the full event pdf is allowed to vary around the nominal shape within an μμ γ selection, inclusive ϒðnSÞ production accounts for 7% of envelope associated with shifts in the pT and pT distri- events, 27% of the events are produced in Z → μþμ−γ butions. Furthermore, a separate background model, gen- decays, and 66% of the events are associated with combi- erated without removing the contamination from þ − natoric backgrounds from nonresonant dimuon events. The Z → μ μ γ decays, provides an upper bound on potential contribution from Z → μþμ−γ decays is in agreement with mismodeling associated with this process. the MC expectation. Results are extracted by means of a simultaneous Trigger efficiencies and efficiencies for muon and unbinned maximum likelihood fit, performed to the photon identification are determined from samples of selected events with 30 GeV

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80 ATLAS 50 ATLAS 35 ATLAS sV=8 Te ∫Ldt = 20.3 fb-1 sV=8 Te ∫Ldt = 20.3 fb-1 sV=8 Te ∫Ldt = 20.3 fb-1 70 Data Data 30 Data S+B Fit 40 S+B Fit S+B Fit 60 Combinatoric Combinatoric Combinatoric ϒ(nS) ϒ(nS) 25 ϒ(nS) Z FSR Z FSR Z FSR 50 H [B=10-3] H [B=10-3] H [B=10-3] Z [B=10-6] 30 Z [B=10-6] 20 Z [B=10-6] 40 15 20 Events / 4 GeV 30 Events / 4 GeV

Events / 0.125 GeV 10 20 10 10 5 0 0 40 80 120 160 200 0 50 100 150 200 8 8.5 9 9.5 10 10.5 11 11.5 12 μμγ m μμγ [GeV] p [GeV] T mμμ [GeV]

μμγ FIG. 2 (color online). The mμμγ, pT , and mμμ distributions of the selected ϒðnSÞγ candidates, along with the results of the unbinned maximum likelihood fit to the signal and background model (S þ B fit). The error bars on the data points correspond to the statistical uncertainties. The Higgs and Z boson contributions as expected for branching fraction values of 10−3 and 10−6, respectively, for each of the ϒðnSÞ are also shown. signal is profiled (allowed to float to the values that We thank CERN for the very successful operation maximize the likelihood) during the fit. of the LHC, as well as the support staff from our In conclusion, the first search for the decays of the SM institutions without whom ATLAS could not be operated Higgs and Z bosons topJ=ffiffiffi ψγ and ϒðnSÞγ (n ¼ 1; 2; 3) has efficiently. We acknowledge the support of ANPCyT, been performed with s ¼ 8 TeV pp collision data sam- Argentina; YerPhI, Armenia; ARC, Australia; BMWFW ples corresponding to integrated luminosities of up to and FWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; −1 20.3 fb collected with the ATLAS detector at the LHC. CNPq and FAPESP, Brazil; NSERC, NRC and CFI, No significant excess of events is observed above the Canada; CERN; CONICYT, Chile; CAS, MOST and J=ψγ background. In the final state, the 95% C.L. upper NSFC, China; COLCIENCIAS, Colombia; MSMT CR, limits on the relevant branching fractions for the SM Higgs MPO CR and VSC CR, Czech Republic; DNRF, DNSRC Z 1 5 10−3 2 6 10−6 and bosons are . × and . × , respectively. and Lundbeck Foundation, Denmark; EPLANET, ERC ϒð1S; 2S; 3SÞγ The corresponding upper limits in the and NSRF, European Union; IN2P3-CNRS, CEA-DSM/ ð1 3;1 9;1 3Þ 10−3 ð3 4;6 5;5 4Þ 10−6 channels are . . . × and . . . × , IRFU, France; GNSF, Georgia; BMBF, DFG, HGF, Z for the SM Higgs and bosons, respectively. These are the MPG and AvH Foundation, Germany; GSRT and first experimental bounds on exclusive Higgs and Z boson NSRF, Greece; ISF, MINERVA, GIF, I-CORE and decays to final states involving quarkonia. Benoziyo Center, Israel; INFN, Italy; MEXT and JSPS, Japan; CNRST, Morocco; FOM and NWO, Netherlands; BRF and RCN, Norway; MNiSW and NCN, Poland; TABLE II. Expectedpffiffiffi and observed branching fraction limits at 95% C.L. for s ¼ 8 TeV. The 1σ fluctuations of the expected GRICES and FCT, Portugal; MNE/IFA, Romania; MES of limits are also given. For the Higgs decay search, limits are Russia and ROSATOM, Russian Federation; JINR; also set on the cross section times branching fraction MSTD, Serbia; MSSR, Slovakia; ARRS and MIZŠ, σðpp → HÞ × BðH → QγÞ. Slovenia; DST/NRF, South Africa; MINECO, Spain; SRC and Wallenberg Foundation, Sweden; SER, SNSF 95% C.L. upper limits P and Cantons of Bern and Geneva, Switzerland; NSC, J=ψ ϒð1SÞ ϒð2SÞ ϒð3SÞ ϒðnSÞ n Taiwan; TAEK, Turkey; STFC, the Royal Society and BðZ → QγÞ½10−6 Leverhulme Trust, United Kingdom; DOE and NSF, 2 0þ1.0 4 9þ2.5 6 2þ3.2 5 4þ2.7 8 8þ4.7 Expected . −0.6 . −1.4 . −1.8 . −1.5 . −2.5 United States of America. The crucial computing support Observed 2.6 3.4 6.5 5.4 7.9 from all WLCG partners is acknowledged gratefully, in BðH → QγÞ½10−3 particular from CERN and the ATLAS Tier-1 facilities at Expected 1 2þ0.6 1 8þ0.9 2 1þ1.1 1 8þ0.9 2 5þ1.3 . −0.3 . −0.5 . −0.6 . −0.5 . −0.7 TRIUMF (Canada), NDGF (Denmark, Norway, Sweden), Observed 1.5 1.3 1.9 1.3 2.0 CC-IN2P3 (France), KIT/GridKA (Germany), INFN- σðpp → HÞ BðH → QγÞ½ × fb CNAF (Italy), NL-T1 (Netherlands), PIC (Spain), Expected 26þ12 38þ19 45þ24 38þ19 54þ27 −7 −11 −13 −11 −15 ASGC (Taiwan), RAL (UK) and BNL (USA) and in Observed 33 29 41 28 44 the Tier-2 facilities worldwide.

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[1] ATLAS Collaboration, Phys. Lett. B 716, 1 (2012). [24] P. Nason, J. High Energy Phys. 11 (2004) 040. [2] CMS Collaboration, Phys. Lett. B 716, 30 (2012). [25] S. Frixione, P. Nason, and C. Oleari, J. High Energy Phys. [3] M. Doroshenko, V. Kartvelishvili, E. Chikovani, and S. 11 (2007) 070. Esakiya, Yad. Fiz. 46, 864 (1987). [26] S. Alioli, P. Nason, C. Oleari, and E. Re, J. High Energy [4] G. T. Bodwin, F. Petriello, S. Stoynev, and M. Velasco, Phys. 06 (2010) 043. Phys. Rev. D 88, 053003 (2013). [27] S. Alioli, P. Nason, C. Oleari, and E. Re, J. High Energy [5] G. T. Bodwin, H. S. Chung, J.-H. Ee, J. Lee, and F. Petriello, Phys. 04 (2009) 002. Phys. Rev. D 90, 113010 (2014). [28] P. Nason and C. Oleari, J. High Energy Phys. 02 (2010) 037. [6] A. L. Kagan, G. Perez, F. Petriello, Y. Soreq, S. Stoynev, and [29] D. de Florian, G. Ferrera, M. Grazzini, and D. Tommasini, J. J. Zupan, Phys. Rev. Lett. 114, LT14571 (2015). High Energy Phys. 06 (2012) 132. [7] C. Delaunay, T. Golling, G. Perez, and Y. Soreq, Phys. Rev. [30] M. Grazzini and H. Sargsyan, J. High Energy Phys. 09 D 89, 033014 (2014). (2013) 129. [8] G. F. Giudice and O. Lebedev, Phys. Lett. B 665, 79 (2008). [31] E. Bagnaschi, G. Degrassi, P. Slavich, and A. Vicini, J. High [9] A. L. Kagan, G. Perez, T. Volansky, and J. Zupan, Phys. Energy Phys. 02 (2012) 088. Rev. D 80, 076002 (2009). [32] LHC Higgs Cross Section Working Group, S. Heinemeyer, [10] B. Bhattacharya, A. Datta, and D. London, Phys. Lett. B C. Mariotti, G. Passarino, and R. Tanaka, arXiv:1307.1347. 736, 421 (2014). [33] A. Firan and R. Stroynowski, Phys. Rev. D 76, 057301 [11] M. Perez, G. Tavares-Velasco, and J. Toscano, Int. J. Mod. (2007). Phys. A 19, 159 (2004). [34] Y. Sun and D.-N. Gao, Phys. Rev. D 89, 017301 (2014). [12] B. Guberina, J. H. Kuhn, R. Peccei, and R. Ruckl, Nucl. [35] A. Y. Korchin and V. A. Kovalchuk, Eur. Phys. J. C 74, 3141 Phys. B174, 317 (1980). (2014). [13] N. Achasov, Theor. Math. Phys. 170, 39 (2012). [36] C. Anastasiou, L. J. Dixon, K. Melnikov, and F. Petriello, [14] T.-C. Huang and F. Petriello, arXiv:1411.5924. Phys. Rev. D 69, 094008 (2004). [15] J. Lansberg, Phys. Lett. B 679, 340 (2009). [37] T. Sjostrand, S. Mrenna, and P. Z. Skands, J. High Energy [16] R. Li and J.-X. Wang, Phys. Rev. D 89, 114018 (2014). Phys. 05 (2006) 026. [17] K. A. Olive et al. (Particle Data Group), Chin. Phys. C 38, [38] T. Sjostrand, S. Mrenna, and P. Z. Skands, Comput. Phys. 090001 (2014). Commun. 178, 852 (2008). [18] M. Acciarri et al. (L3 Collaboration), Phys. Lett. B 453,94 [39] P. Golonka and Z. Was, Eur. Phys. J. C 45, 97 (2006). (1999). [40] N. Davidson, T. Przedzinski, and Z. Was, arXiv:1011.0937. [19] G. Alexander et al. (OPAL Collaboration), Z. Phys. C 70, [41] S. Agostinelli et al., Nucl. Instrum. Methods Phys. Res., 197 (1996). Sect. A 506, 250 (2003). [20] P. Abreu et al. (DELPHI Collaboration), Phys. Lett. B 341, [42] ATLAS Collaboration, Eur. Phys. J. C 70, 823 (2010). 109 (1994). [43] ATLAS Collaboration, Eur. Phys. J. C 74, 3130 (2014). [21] G. Alexander et al. (OPAL Collaboration), Phys. Lett. B [44] ATLAS Collaboration, Tech. Report No. ATL-PHYS-PUB- 370, 185 (1996). 2011-007, 2011, https://cds.cern.ch/record/1345329. [22] ATLAS uses a right-handed coordinate system with its [45] ATLAS Collaboration, Phys. Rev. D 83, 052005 (2011). origin at the nominal interaction point (IP) in the center of [46] K. S. Cranmer, Comput. Phys. Commun. 136, 198 (2001). the detector and the z axis along the beam pipe. The x axis [47] ATLAS Collaboration, Report No. ATLAS-CONF-2012- points from the IP to the center of the LHC ring, and the y 123, 2012. axis points upward. Cylindrical coordinates (r; ϕ) are used [48] ATLAS Collaboration, Eur. Phys. J. C 73, 2518 (2013). in the transverse plane, ϕ being the azimuthal angle around [49] ATLAS Collaboration, Eur. Phys. J. C 74, 3071 (2014). the beam pipe. The pseudorapidity is defined in terms of the [50] A. L. Read, J. Phys. G 28, 2693 (2002). polar angle θ as η ¼ − ln tanðθ=2Þ. [51] G. Cowan, K. Cranmer, E. Gross, and O. Vitells, Eur. Phys. [23] ATLAS Collaboration, JINST 3, S08003 (2008). J. C 71, 1554 (2011).

G. Aad,85 B. Abbott,113 J. Abdallah,152 S. Abdel Khalek,117 O. Abdinov,11 R. Aben,107 B. Abi,114 M. Abolins,90 O. S. AbouZeid,159 H. Abramowicz,154 H. Abreu,153 R. Abreu,30 Y. Abulaiti,147a,147b B. S. Acharya,165a,165b,b L. Adamczyk,38a D. L. Adams,25 J. Adelman,108 S. Adomeit,100 T. Adye,131 T. Agatonovic-Jovin,13 J. A. Aguilar-Saavedra,126a,126f M. Agustoni,17 S. P. Ahlen,22 F. Ahmadov,65,c G. Aielli,134a,134b H. Akerstedt,147a,147b T. P. A. Åkesson,81 G. Akimoto,156 A. V. Akimov,96 G. L. Alberghi,20a,20b J. Albert,170 S. Albrand,55 M. J. Alconada Verzini,71 M. Aleksa,30 I. N. Aleksandrov,65 C. Alexa,26a G. Alexander,154 G. Alexandre,49 T. Alexopoulos,10 M. Alhroob,113 G. Alimonti,91a L. Alio,85 J. Alison,31 B. M. M. Allbrooke,18 L. J. Allison,72 P. P. Allport,74 A. Aloisio,104a,104b A. Alonso,36 F. Alonso,71 C. Alpigiani,76 A. Altheimer,35 B. Alvarez Gonzalez,90 M. G. Alviggi,104a,104b K. Amako,66 Y. Amaral Coutinho,24a C. Amelung,23 D. Amidei,89 S. P. Amor Dos Santos,126a,126c A. Amorim,126a,126b S. Amoroso,48 N. Amram,154 G. Amundsen,23 C. Anastopoulos,140 L. S. Ancu,49 N. Andari,30 T. Andeen,35 C. F. Anders,58b

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G. Anders,30 K. J. Anderson,31 A. Andreazza,91a,91b V. Andrei,58a X. S. Anduaga,71 S. Angelidakis,9 I. Angelozzi,107 P. Anger,44 A. Angerami,35 F. Anghinolfi,30 A. V. Anisenkov,109,d N. Anjos,12 A. Annovi,124a,124b M. Antonelli,47 A. Antonov,98 J. Antos,145b F. Anulli,133a M. Aoki,66 L. Aperio Bella,18 G. Arabidze,90 Y. Arai,66 J. P. Araque,126a A. T. H. Arce,45 F. A. Arduh,71 J-F. Arguin,95 S. Argyropoulos,42 M. Arik,19a A. J. Armbruster,30 O. Arnaez,30 V. Arnal,82 H. Arnold,48 M. Arratia,28 O. Arslan,21 A. Artamonov,97 G. Artoni,23 S. Asai,156 N. Asbah,42 A. Ashkenazi,154 B. Åsman,147a,147b L. Asquith,150 K. Assamagan,25 R. Astalos,145a M. Atkinson,166 N. B. Atlay,142 B. Auerbach,6 K. Augsten,128 M. Aurousseau,146b G. Avolio,30 B. Axen,15 M. K. Ayoub,117 G. Azuelos,95,e M. A. Baak,30 A. E. Baas,58a C. Bacci,135a,135b H. Bachacou,137 K. Bachas,155 M. Backes,30 M. Backhaus,30 P. Bagiacchi,133a,133b P. Bagnaia,133a,133b Y. Bai,33a T. Bain,35 J. T. Baines,131 O. K. Baker,177 P. Balek,129 T. Balestri,149 F. Balli,84 E. Banas,39 Sw. Banerjee,174 A. A. E. Bannoura,176 H. S. Bansil,18 L. Barak,173 S. P. Baranov,96 E. L. Barberio,88 D. Barberis,50a,50b M. Barbero,85 T. Barillari,101 M. Barisonzi,165a,165b T. Barklow,144 N. Barlow,28 S. L. Barnes,84 B. M. Barnett,131 R. M. Barnett,15 Z. Barnovska,5 A. Baroncelli,135a G. Barone,49 A. J. Barr,120 F. Barreiro,82 J. Barreiro Guimarães da Costa,57 R. Bartoldus,144 A. E. Barton,72 P. Bartos,145a A. Bassalat,117 A. Basye,166 R. L. Bates,53 S. J. Batista,159 J. R. Batley,28 M. Battaglia,138 M. Bauce,133a,133b F. Bauer,137 H. S. Bawa,144,f J. B. Beacham,111 M. D. Beattie,72 T. Beau,80 P. H. Beauchemin,162 R. Beccherle,124a,124b P. Bechtle,21 H. P. Beck,17,g K. Becker,120 S. Becker,100 M. Beckingham,171 C. Becot,117 A. J. Beddall,19c A. Beddall,19c V. A. Bednyakov,65 C. P. Bee,149 L. J. Beemster,107 T. A. Beermann,176 M. Begel,25 K. Behr,120 C. Belanger-Champagne,87 P. J. Bell,49 W. H. Bell,49 G. Bella,154 L. Bellagamba,20a A. Bellerive,29 M. Bellomo,86 K. Belotskiy,98 O. Beltramello,30 O. Benary,154 D. Benchekroun,136a M. Bender,100 K. Bendtz,147a,147b N. Benekos,10 Y. Benhammou,154 E. Benhar Noccioli,49 J. A. Benitez Garcia,160b D. P. Benjamin,45 J. R. Bensinger,23 S. Bentvelsen,107 L. Beresford,120 M. Beretta,47 D. Berge,107 E. Bergeaas Kuutmann,167 N. Berger,5 F. Berghaus,170 J. Beringer,15 C. Bernard,22 N. R. Bernard,86 C. Bernius,110 F. U. Bernlochner,21 T. Berry,77 P. Berta,129 C. Bertella,83 G. Bertoli,147a,147b F. Bertolucci,124a,124b C. Bertsche,113 D. Bertsche,113 M. I. Besana,91a G. J. Besjes,106 O. Bessidskaia Bylund,147a,147b M. Bessner,42 N. Besson,137 C. Betancourt,48 S. Bethke,101 A. J. Bevan,76 W. Bhimji,46 R. M. Bianchi,125 L. Bianchini,23 M. Bianco,30 O. Biebel,100 S. P. Bieniek,78 M. Biglietti,135a J. Bilbao De Mendizabal,49 H. Bilokon,47 M. Bindi,54 S. Binet,117 A. Bingul,19c C. Bini,133a,133b C. W. Black,151 J. E. Black,144 K. M. Black,22 D. Blackburn,139 R. E. Blair,6 J.-B. Blanchard,137 J. E. Blanco,77 T. Blazek,145a I. Bloch,42 C. Blocker,23 W. Blum,83,a U. Blumenschein,54 G. J. Bobbink,107 V. S. Bobrovnikov,109,d S. S. Bocchetta,81 A. Bocci,45 C. Bock,100 C. R. Boddy,120 M. Boehler,48 J. A. Bogaerts,30 A. G. Bogdanchikov,109 C. Bohm,147a V. Boisvert,77 T. Bold,38a V. Boldea,26a A. S. Boldyrev,99 M. Bomben,80 M. Bona,76 M. Boonekamp,137 A. Borisov,130 G. Borissov,72 S. Borroni,42 J. Bortfeldt,100 V. Bortolotto,60a K. Bos,107 D. Boscherini,20a M. Bosman,12 J. Boudreau,125 J. Bouffard,2 E. V. Bouhova-Thacker,72 D. Boumediene,34 C. Bourdarios,117 N. Bousson,114 S. Boutouil,136d A. Boveia,30 J. Boyd,30 I. R. Boyko,65 I. Bozic,13 J. Bracinik,18 A. Brandt,8 G. Brandt,15 O. Brandt,58a U. Bratzler,157 B. Brau,86 J. E. Brau,116 H. M. Braun,176,a S. F. Brazzale,165a,165c K. Brendlinger,122 A. J. Brennan,88 L. Brenner,107 R. Brenner,167 S. Bressler,173 K. Bristow,146c T. M. Bristow,46 D. Britton,53 F. M. Brochu,28 I. Brock,21 R. Brock,90 J. Bronner,101 G. Brooijmans,35 T. Brooks,77 W. K. Brooks,32b J. Brosamer,15 E. Brost,116 J. Brown,55 P. A. Bruckman de Renstrom,39 D. Bruncko,145b R. Bruneliere,48 A. Bruni,20a G. Bruni,20a M. Bruschi,20a L. Bryngemark,81 T. Buanes,14 Q. Buat,143 F. Bucci,49 P. Buchholz,142 A. G. Buckley,53 S. I. Buda,26a I. A. Budagov,65 F. Buehrer,48 L. Bugge,119 M. K. Bugge,119 O. Bulekov,98 H. Burckhart,30 S. Burdin,74 B. Burghgrave,108 S. Burke,131 I. Burmeister,43 E. Busato,34 D. Büscher,48 V. Büscher,83 P. Bussey,53 C. P. Buszello,167 J. M. Butler,22 A. I. Butt,3 C. M. Buttar,53 J. M. Butterworth,78 P. Butti,107 W. Buttinger,25 A. Buzatu,53 S. Cabrera Urbán,168 D. Caforio,128 O. Cakir,4a P. Calafiura,15 A. Calandri,137 G. Calderini,80 P. Calfayan,100 L. P. Caloba,24a D. Calvet,34 S. Calvet,34 R. Camacho Toro,49 S. Camarda,42 D. Cameron,119 L. M. Caminada,15 R. Caminal Armadans,12 S. Campana,30 M. Campanelli,78 A. Campoverde,149 V. Canale,104a,104b A. Canepa,160a M. Cano Bret,76 J. Cantero,82 R. Cantrill,126a T. Cao,40 M. D. M. Capeans Garrido,30 I. Caprini,26a M. Caprini,26a M. Capua,37a,37b R. Caputo,83 R. Cardarelli,134a T. Carli,30 G. Carlino,104a L. Carminati,91a,91b S. Caron,106 E. Carquin,32a G. D. Carrillo-Montoya,146c J. R. Carter,28 J. Carvalho,126a,126c D. Casadei,78 M. P. Casado,12 M. Casolino,12 E. Castaneda-Miranda,146b A. Castelli,107 V. Castillo Gimenez,168 N. F. Castro,126a P. Catastini,57 A. Catinaccio,30 J. R. Catmore,119 A. Cattai,30 G. Cattani,134a,134b J. Caudron,83 V. Cavaliere,166 D. Cavalli,91a M. Cavalli-Sforza,12 V. Cavasinni,124a,124b F. Ceradini,135a,135b B. C. Cerio,45 K. Cerny,129 A. S. Cerqueira,24b A. Cerri,150 L. Cerrito,76 F. Cerutti,15 M. Cerv,30 A. Cervelli,17 S. A. Cetin,19b A. Chafaq,136a D. Chakraborty,108 I. Chalupkova,129 P. Chang,166 B. Chapleau,87 J. D. Chapman,28 D. Charfeddine,117 D. G. Charlton,18

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C. C. Chau,159 C. A. Chavez Barajas,150 S. Cheatham,153 A. Chegwidden,90 S. Chekanov,6 S. V. Chekulaev,160a G. A. Chelkov,65,h M. A. Chelstowska,89 C. Chen,64 H. Chen,25 K. Chen,149 L. Chen,33d,i S. Chen,33c X. Chen,33f Y. Chen,67 H. C. Cheng,89 Y. Cheng,31 A. Cheplakov,65 E. Cheremushkina,130 R. Cherkaoui El Moursli,136e V. Chernyatin,25,a E. Cheu,7 L. Chevalier,137 V. Chiarella,47 J. T. Childers,6 A. Chilingarov,72 G. Chiodini,73a A. S. Chisholm,18 R. T. Chislett,78 A. Chitan,26a M. V. Chizhov,65 S. Chouridou,9 B. K. B. Chow,100 D. Chromek-Burckhart,30 M. L. Chu,152 J. Chudoba,127 J. J. Chwastowski,39 L. Chytka,115 G. Ciapetti,133a,133b A. K. Ciftci,4a D. Cinca,53 V. Cindro,75 A. Ciocio,15 Z. H. Citron,173 M. Citterio,91a M. Ciubancan,26a A. Clark,49 P. J. Clark,46 R. N. Clarke,15 W. Cleland,125 C. Clement,147a,147b Y. Coadou,85 M. Cobal,165a,165c A. Coccaro,139 J. Cochran,64 L. Coffey,23 J. G. Cogan,144 B. Cole,35 S. Cole,108 A. P. Colijn,107 J. Collot,55 T. Colombo,58c G. Compostella,101 P. Conde Muiño,126a,126b E. Coniavitis,48 S. H. Connell,146b I. A. Connelly,77 S. M. Consonni,91a,91b V. Consorti,48 S. Constantinescu,26a C. Conta,121a,121b G. Conti,30 F. Conventi,104a,j M. Cooke,15 B. D. Cooper,78 A. M. Cooper-Sarkar,120 K. Copic,15 T. Cornelissen,176 M. Corradi,20a F. Corriveau,87,k A. Corso-Radu,164 A. Cortes-Gonzalez,12 G. Cortiana,101 M. J. Costa,168 D. Costanzo,140 D. Côté,8 G. Cottin,28 G. Cowan,77 B. E. Cox,84 K. Cranmer,110 G. Cree,29 S. Crépé-Renaudin,55 F. Crescioli,80 W. A. Cribbs,147a,147b M. Crispin Ortuzar,120 M. Cristinziani,21 V. Croft,106 G. Crosetti,37a,37b T. Cuhadar Donszelmann,140 J. Cummings,177 M. Curatolo,47 C. Cuthbert,151 H. Czirr,142 P. Czodrowski,3 S. D’Auria,53 M. D’Onofrio,74 M. J. Da Cunha Sargedas De Sousa,126a,126b C. Da Via,84 W. Dabrowski,38a A. Dafinca,120 T. Dai,89 O. Dale,14 F. Dallaire,95 C. Dallapiccola,86 M. Dam,36 J. R. Dandoy,31 A. C. Daniells,18 M. Danninger,169 M. Dano Hoffmann,137 V. Dao,48 G. Darbo,50a S. Darmora,8 J. Dassoulas,3 A. Dattagupta,61 W. Davey,21 C. David,170 T. Davidek,129 E. Davies,120,l M. Davies,154 O. Davignon,80 P. Davison,78 Y. Davygora,58a E. Dawe,143 I. Dawson,140 R. K. Daya-Ishmukhametova,86 K. De,8 R. de Asmundis,104a S. De Castro,20a,20b S. De Cecco,80 N. De Groot,106 P. de Jong,107 H. De la Torre,82 F. De Lorenzi,64 L. De Nooij,107 D. De Pedis,133a A. De Salvo,133a U. De Sanctis,150 A. De Santo,150 J. B. De Vivie De Regie,117 W. J. Dearnaley,72 R. Debbe,25 C. Debenedetti,138 D. V. Dedovich,65 I. Deigaard,107 J. Del Peso,82 T. Del Prete,124a,124b D. Delgove,117 F. Deliot,137 C. M. Delitzsch,49 M. Deliyergiyev,75 A. Dell’Acqua,30 L. Dell’Asta,22 M. Dell’Orso,124a,124b M. Della Pietra,104a,j D. della Volpe,49 M. Delmastro,5 P. A. Delsart,55 C. Deluca,107 D. A. DeMarco,159 S. Demers,177 M. Demichev,65 A. Demilly,80 S. P. Denisov,130 D. Derendarz,39 J. E. Derkaoui,136d F. Derue,80 P. Dervan,74 K. Desch,21 C. Deterre,42 P. O. Deviveiros,30 A. Dewhurst,131 S. Dhaliwal,107 A. Di Ciaccio,134a,134b L. Di Ciaccio,5 A. Di Domenico,133a,133b C. Di Donato,104a,104b A. Di Girolamo,30 B. Di Girolamo,30 A. Di Mattia,153 B. Di Micco,135a,135b R. Di Nardo,47 A. Di Simone,48 R. Di Sipio,20a,20b D. Di Valentino,29 C. Diaconu,85 M. Diamond,159 F. A. Dias,46 M. A. Diaz,32a E. B. Diehl,89 J. Dietrich,16 T. A. Dietzsch,58a S. Diglio,85 A. Dimitrievska,13 J. Dingfelder,21 F. Dittus,30 F. Djama,85 T. Djobava,51b J. I. Djuvsland,58a M. A. B. do Vale,24c D. Dobos,30 M. Dobre,26a C. Doglioni,49 T. Doherty,53 T. Dohmae,156 J. Dolejsi,129 Z. Dolezal,129 B. A. Dolgoshein,98,a M. Donadelli,24d S. Donati,124a,124b P. Dondero,121a,121b J. Donini,34 J. Dopke,131 A. Doria,104a M. T. Dova,71 A. T. Doyle,53 M. Dris,10 E. Dubreuil,34 E. Duchovni,173 G. Duckeck,100 O. A. Ducu,26a D. Duda,176 A. Dudarev,30 L. Duflot,117 L. Duguid,77 M. Dührssen,30 M. Dunford,58a H. Duran Yildiz,4a M. Düren,52 A. Durglishvili,51b D. Duschinger,44 M. Dwuznik,38a M. Dyndal,38a W. Edson,2 N. C. Edwards,46 W. Ehrenfeld,21 T. Eifert,30 G. Eigen,14 K. Einsweiler,15 T. Ekelof,167 M. El Kacimi,136c M. Ellert,167 S. Elles,5 F. Ellinghaus,83 A. A. Elliot,170 N. Ellis,30 J. Elmsheuser,100 M. Elsing,30 D. Emeliyanov,131 Y. Enari,156 O. C. Endner,83 M. Endo,118 R. Engelmann,149 J. Erdmann,43 A. Ereditato,17 D. Eriksson,147a G. Ernis,176 J. Ernst,2 M. Ernst,25 S. Errede,166 E. Ertel,83 M. Escalier,117 H. Esch,43 C. Escobar,125 B. Esposito,47 A. I. Etienvre,137 E. Etzion,154 H. Evans,61 A. Ezhilov,123 L. Fabbri,20a,20b G. Facini,31 R. M. Fakhrutdinov,130 S. Falciano,133a R. J. Falla,78 J. Faltova,129 Y. Fang,33a M. Fanti,91a,91b A. Farbin,8 A. Farilla,135a T. Farooque,12 S. Farrell,15 S. M. Farrington,171 P. Farthouat,30 F. Fassi,136e P. Fassnacht,30 D. Fassouliotis,9 A. Favareto,50a,50b L. Fayard,117 P. Federic,145a O. L. Fedin,123,m W. Fedorko,169 S. Feigl,30 L. Feligioni,85 C. Feng,33d E. J. Feng,6 H. Feng,89 A. B. Fenyuk,130 P. Fernandez Martinez,168 S. Fernandez Perez,30 S. Ferrag,53 J. Ferrando,53 A. Ferrari,167 P. Ferrari,107 R. Ferrari,121a D. E. Ferreira de Lima,53 A. Ferrer,168 D. Ferrere,49 C. Ferretti,89 A. Ferretto Parodi,50a,50b M. Fiascaris,31 F. Fiedler,83 A. Filipčič,75 M. Filipuzzi,42 F. Filthaut,106 M. Fincke-Keeler,170 K. D. Finelli,151 M. C. N. Fiolhais,126a,126c L. Fiorini,168 A. Firan,40 A. Fischer,2 C. Fischer,12 J. Fischer,176 W. C. Fisher,90 E. A. Fitzgerald,23 M. Flechl,48 I. Fleck,142 P. Fleischmann,89 S. Fleischmann,176 G. T. Fletcher,140 G. Fletcher,76 T. Flick,176 A. Floderus,81 L. R. Flores Castillo,60a M. J. Flowerdew,101 A. Formica,137 A. Forti,84 D. Fournier,117 H. Fox,72 S. Fracchia,12 P. Francavilla,80 M. Franchini,20a,20b D. Francis,30 L. Franconi,119 M. Franklin,57 M. Fraternali,121a,121b D. Freeborn,78 S. T. French,28 F. Friedrich,44 D. Froidevaux,30 J. A. Frost,120 C. Fukunaga,157 E. Fullana Torregrosa,83 B. G. Fulsom,144

121801-8 week ending PRL 114, 121801 (2015) PHYSICAL REVIEW LETTERS 27 MARCH 2015

J. Fuster,168 C. Gabaldon,55 O. Gabizon,176 A. Gabrielli,20a,20b A. Gabrielli,133a,133b S. Gadatsch,107 S. Gadomski,49 G. Gagliardi,50a,50b P. Gagnon,61 C. Galea,106 B. Galhardo,126a,126c E. J. Gallas,120 B. J. Gallop,131 P. Gallus,128 G. Galster,36 K. K. Gan,111 J. Gao,33b,85 Y. S. Gao,144,f F. M. Garay Walls,46 F. Garberson,177 C. García,168 J. E. García Navarro,168 M. Garcia-Sciveres,15 R. W. Gardner,31 N. Garelli,144 V. Garonne,30 C. Gatti,47 G. Gaudio,121a B. Gaur,142 L. Gauthier,95 P. Gauzzi,133a,133b I. L. Gavrilenko,96 C. Gay,169 G. Gaycken,21 E. N. Gazis,10 P. Ge, 33d Z. Gecse,169 C. N. P. Gee,131 D. A. A. Geerts,107 Ch. Geich-Gimbel,21 C. Gemme,50a M. H. Genest,55 S. Gentile,133a,133b M. George,54 S. George,77 D. Gerbaudo,164 A. Gershon,154 H. Ghazlane,136b N. Ghodbane,34 B. Giacobbe,20a S. Giagu,133a,133b V. Giangiobbe,12 P. Giannetti,124a,124b F. Gianotti,30 B. Gibbard,25 S. M. Gibson,77 M. Gilchriese,15 T. P. S. Gillam,28 D. Gillberg,30 G. Gilles,34 D. M. Gingrich,3,e N. Giokaris,9 M. P. Giordani,165a,165c F. M. Giorgi,20a F. M. Giorgi,16 P. F. Giraud,137 D. Giugni,91a C. Giuliani,48 M. Giulini,58b B. K. Gjelsten,119 S. Gkaitatzis,155 I. Gkialas,155 E. L. Gkougkousis,117 L. K. Gladilin,99 C. Glasman,82 J. Glatzer,30 P. C. F. Glaysher,46 A. Glazov,42 M. Goblirsch-Kolb,101 J. R. Goddard,76 J. Godlewski,39 S. Goldfarb,89 T. Golling,49 D. Golubkov,130 A. Gomes,126a,126b,126d R. Gonçalo,126a J. Goncalves Pinto Firmino Da Costa,137 L. Gonella,21 S. González de la Hoz,168 G. Gonzalez Parra,12 S. Gonzalez-Sevilla,49 L. Goossens,30 P. A. Gorbounov,97 H. A. Gordon,25 I. Gorelov,105 B. Gorini,30 E. Gorini,73a,73b A. Gorišek,75 E. Gornicki,39 A. T. Goshaw,45 C. Gössling,43 M. I. Gostkin,65 M. Gouighri,136a D. Goujdami,136c A. G. Goussiou,139 H. M. X. Grabas,138 L. Graber,54 I. Grabowska-Bold,38a P. Grafström,20a,20b K-J. Grahn,42 J. Gramling,49 E. Gramstad,119 S. Grancagnolo,16 V. Grassi,149 V. Gratchev,123 H. M. Gray,30 E. Graziani,135a Z. D. Greenwood,79,n K. Gregersen,78 I. M. Gregor,42 P. Grenier,144 J. Griffiths,8 A. A. Grillo,138 K. Grimm,72 S. Grinstein,12,o Ph. Gris,34 Y. V. Grishkevich,99 J.-F. Grivaz,117 J. P. Grohs,44 A. Grohsjean,42 E. Gross,173 J. Grosse-Knetter,54 G. C. Grossi,134a,134b Z. J. Grout,150 L. Guan,33b J. Guenther,128 F. Guescini,49 D. Guest,177 O. Gueta,154 E. Guido,50a,50b T. Guillemin,117 S. Guindon,2 U. Gul,53 C. Gumpert,44 J. Guo,33e S. Gupta,120 P. Gutierrez,113 N. G. Gutierrez Ortiz,53 C. Gutschow,44 N. Guttman,154 C. Guyot,137 C. Gwenlan,120 C. B. Gwilliam,74 A. Haas,110 C. Haber,15 H. K. Hadavand,8 N. Haddad,136e P. Haefner,21 S. Hageböck,21 Z. Hajduk,39 H. Hakobyan,178 M. Haleem,42 J. Haley,114 D. Hall,120 G. Halladjian,90 G. D. Hallewell,85 K. Hamacher,176 P. Hamal,115 K. Hamano,170 M. Hamer,54 A. Hamilton,146a S. Hamilton,162 G. N. Hamity,146c P. G. Hamnett,42 L. Han,33b K. Hanagaki,118 K. Hanawa,156 M. Hance,15 P. Hanke,58a R. Hanna,137 J. B. Hansen,36 J. D. Hansen,36 P. H. Hansen,36 K. Hara,161 A. S. Hard,174 T. Harenberg,176 F. Hariri,117 S. Harkusha,92 R. D. Harrington,46 P. F. Harrison,171 F. Hartjes,107 M. Hasegawa,67 S. Hasegawa,103 Y. Hasegawa,141 A. Hasib,113 S. Hassani,137 S. Haug,17 R. Hauser,90 L. Hauswald,44 M. Havranek,127 C. M. Hawkes,18 R. J. Hawkings,30 A. D. Hawkins,81 T. Hayashi,161 D. Hayden,90 C. P. Hays,120 J. M. Hays,76 H. S. Hayward,74 S. J. Haywood,131 S. J. Head,18 T. Heck,83 V. Hedberg,81 L. Heelan,8 S. Heim,122 T. Heim,176 B. Heinemann,15 L. Heinrich,110 J. Hejbal,127 L. Helary,22 M. Heller,30 S. Hellman,147a,147b D. Hellmich,21 C. Helsens,30 J. Henderson,120 R. C. W. Henderson,72 Y. Heng,174 C. Hengler,42 A. Henrichs,177 A. M. Henriques Correia,30 S. Henrot-Versille,117 G. H. Herbert,16 Y. Hernández Jiménez,168 R. Herrberg-Schubert,16 G. Herten,48 R. Hertenberger,100 L. Hervas,30 G. G. Hesketh,78 N. P. Hessey,107 R. Hickling,76 E. Higón-Rodriguez,168 E. Hill,170 J. C. Hill,28 K. H. Hiller,42 S. J. Hillier,18 I. Hinchliffe,15 E. Hines,122 R. R. Hinman,15 M. Hirose,158 D. Hirschbuehl,176 J. Hobbs,149 N. Hod,107 M. C. Hodgkinson,140 P. Hodgson,140 A. Hoecker,30 M. R. Hoeferkamp,105 F. Hoenig,100 M. Hohlfeld,83 T. R. Holmes,15 T. M. Hong,122 L. Hooft van Huysduynen,110 W. H. Hopkins,116 Y. Horii,103 A. J. Horton,143 J-Y. Hostachy,55 S. Hou,152 A. Hoummada,136a J. Howard,120 J. Howarth,42 M. Hrabovsky,115 I. Hristova,16 J. Hrivnac,117 T. Hryn’ova,5 A. Hrynevich,93 C. Hsu,146c P. J. Hsu,152,p S.-C. Hsu,139 D. Hu,35 Q. Hu,33b X. Hu,89 Y. Huang,42 Z. Hubacek,30 F. Hubaut,85 F. Huegging,21 T. B. Huffman,120 E. W. Hughes,35 G. Hughes,72 M. Huhtinen,30 T. A. Hülsing,83 N. Huseynov,65,c J. Huston,90 J. Huth,57 G. Iacobucci,49 G. Iakovidis,25 I. Ibragimov,142 L. Iconomidou-Fayard,117 E. Ideal,177 Z. Idrissi,136e P. Iengo,104a O. Igonkina,107 T. Iizawa,172 Y. Ikegami,66 K. Ikematsu,142 M. Ikeno,66 Y. Ilchenko,31,q D. Iliadis,155 N. Ilic,159 Y. Inamaru,67 T. Ince,101 P. Ioannou,9 M. Iodice,135a K. Iordanidou,9 V. Ippolito,57 A. Irles Quiles,168 C. Isaksson,167 M. Ishino,68 M. Ishitsuka,158 R. Ishmukhametov,111 C. Issever,120 S. Istin,19a J. M. Iturbe Ponce,84 R. Iuppa,134a,134b J. Ivarsson,81 W. Iwanski,39 H. Iwasaki,66 J. M. Izen,41 V. Izzo,104a B. Jackson,122 M. Jackson,74 P. Jackson,1 M. R. Jaekel,30 V. Jain,2 K. Jakobs,48 S. Jakobsen,30 T. Jakoubek,127 J. Jakubek,128 D. O. Jamin,152 D. K. Jana,79 E. Jansen,78 R. W. Jansky,62 J. Janssen,21 M. Janus,171 G. Jarlskog,81 N. Javadov,65,c T. Javůrek,48 L. Jeanty,15 J. Jejelava,51a,r G.-Y. Jeng,151 D. Jennens,88 P. Jenni,48,s J. Jentzsch,43 C. Jeske,171 S. Jézéquel,5 H. Ji,174 J. Jia,149 Y. Jiang,33b J. Jimenez Pena,168 S. Jin,33a A. Jinaru,26a O. Jinnouchi,158 M. D. Joergensen,36 P. Johansson,140 K. A. Johns,7 K. Jon-And,147a,147b G. Jones,171 R. W. L. Jones,72 T. J. Jones,74 J. Jongmanns,58a P. M. Jorge,126a,126b K. D. Joshi,84 J. Jovicevic,148 X. Ju,174 C. A. Jung,43 P. Jussel,62

121801-9 week ending PRL 114, 121801 (2015) PHYSICAL REVIEW LETTERS 27 MARCH 2015

A. Juste Rozas,12,o M. Kaci,168 A. Kaczmarska,39 M. Kado,117 H. Kagan,111 M. Kagan,144 S. J. Kahn,85 E. Kajomovitz,45 C. W. Kalderon,120 S. Kama,40 A. Kamenshchikov,130 N. Kanaya,156 M. Kaneda,30 S. Kaneti,28 V. A. Kantserov,98 J. Kanzaki,66 B. Kaplan,110 A. Kapliy,31 D. Kar,53 K. Karakostas,10 A. Karamaoun,3 N. Karastathis,10,107 M. J. Kareem,54 M. Karnevskiy,83 S. N. Karpov,65 Z. M. Karpova,65 K. Karthik,110 V. Kartvelishvili,72 A. N. Karyukhin,130 L. Kashif,174 R. D. Kass,111 A. Kastanas,14 Y. Kataoka,156 A. Katre,49 J. Katzy,42 K. Kawagoe,70 T. Kawamoto,156 G. Kawamura,54 S. Kazama,156 V. F. Kazanin,109 M. Y. Kazarinov,65 R. Keeler,170 R. Kehoe,40 M. Keil,54 J. S. Keller,42 J. J. Kempster,77 H. Keoshkerian,84 O. Kepka,127 B. P. Kerševan,75 S. Kersten,176 R. A. Keyes,87 F. Khalil-zada,11 H. Khandanyan,147a,147b A. Khanov,114 A. Kharlamov,109 A. Khodinov,98 A. Khomich,58a T. J. Khoo,28 G. Khoriauli,21 V. Khovanskiy,97 E. Khramov,65 J. Khubua,51b,t H. Y. Kim,8 H. Kim,147a,147b S. H. Kim,161 N. Kimura,155 O. Kind,16 B. T. King,74 M. King,168 R. S. B. King,120 S. B. King,169 J. Kirk,131 A. E. Kiryunin,101 T. Kishimoto,67 D. Kisielewska,38a F. Kiss,48 K. Kiuchi,161 E. Kladiva,145b M. H. Klein,35 M. Klein,74 U. Klein,74 K. Kleinknecht,83 P. Klimek,147a,147b A. Klimentov,25 R. Klingenberg,43 J. A. Klinger,84 T. Klioutchnikova,30 P. F. Klok,106 E.-E. Kluge,58a P. Kluit,107 S. Kluth,101 E. Kneringer,62 E. B. F. G. Knoops,85 A. Knue,53 D. Kobayashi,158 T. Kobayashi,156 M. Kobel,44 M. Kocian,144 P. Kodys,129 T. Koffas,29 E. Koffeman,107 L. A. Kogan,120 S. Kohlmann,176 Z. Kohout,128 T. Kohriki,66 T. Koi,144 H. Kolanoski,16 I. Koletsou,5 A. A. Komar,96,a Y. Komori,156 T. Kondo,66 N. Kondrashova,42 K. Köneke,48 A. C. König,106 S. König,83 T. Kono,66,u R. Konoplich,110,v N. Konstantinidis,78 R. Kopeliansky,153 S. Koperny,38a L. Köpke,83 A. K. Kopp,48 K. Korcyl,39 K. Kordas,155 A. Korn,78 A. A. Korol,109,d I. Korolkov,12 E. V. Korolkova,140 O. Kortner,101 S. Kortner,101 T. Kosek,129 V. V. Kostyukhin,21 V. M. Kotov,65 A. Kotwal,45 A. Kourkoumeli-Charalampidi,155 C. Kourkoumelis,9 V. Kouskoura,25 A. Koutsman,160a R. Kowalewski,170 T. Z. Kowalski,38a W. Kozanecki,137 A. S. Kozhin,130 V. A. Kramarenko,99 G. Kramberger,75 D. Krasnopevtsev,98 M. W. Krasny,80 A. Krasznahorkay,30 J. K. Kraus,21 A. Kravchenko,25 S. Kreiss,110 M. Kretz,58c J. Kretzschmar,74 K. Kreutzfeldt,52 P. Krieger,159 K. Krizka,31 K. Kroeninger,43 H. Kroha,101 J. Kroll,122 J. Kroseberg,21 J. Krstic,13 U. Kruchonak,65 H. Krüger,21 N. Krumnack,64 Z. V. Krumshteyn,65 A. Kruse,174 M. C. Kruse,45 M. Kruskal,22 T. Kubota,88 H. Kucuk,78 S. Kuday,4b S. Kuehn,48 A. Kugel,58c F. Kuger,175 A. Kuhl,138 T. Kuhl,42 V. Kukhtin,65 Y. Kulchitsky,92 S. Kuleshov,32b M. Kuna,133a,133b T. Kunigo,68 A. Kupco,127 H. Kurashige,67 Y. A. Kurochkin,92 R. Kurumida,67 V. Kus,127 E. S. Kuwertz,148 M. Kuze,158 J. Kvita,115 T. Kwan,170 D. Kyriazopoulos,140 A. La Rosa,49 J. L. La Rosa Navarro,24d L. La Rotonda,37a,37b C. Lacasta,168 F. Lacava,133a,133b J. Lacey,29 H. Lacker,16 D. Lacour,80 V. R. Lacuesta,168 E. Ladygin,65 R. Lafaye,5 B. Laforge,80 T. Lagouri,177 S. Lai,48 L. Lambourne,78 S. Lammers,61 C. L. Lampen,7 W. Lampl,7 E. Lançon,137 U. Landgraf,48 M. P. J. Landon,76 V. S. Lang,58a A. J. Lankford,164 F. Lanni,25 K. Lantzsch,30 S. Laplace,80 C. Lapoire,30 J. F. Laporte,137 T. Lari,91a F. Lasagni Manghi,20a,20b M. Lassnig,30 P. Laurelli,47 W. Lavrijsen,15 A. T. Law,138 P. Laycock,74 O. Le Dortz,80 E. Le Guirriec,85 E. Le Menedeu,12 T. LeCompte,6 F. Ledroit-Guillon,55 C. A. Lee,146b S. C. Lee,152 L. Lee,1 G. Lefebvre,80 M. Lefebvre,170 F. Legger,100 C. Leggett,15 A. Lehan,74 G. Lehmann Miotto,30 X. Lei,7 W. A. Leight,29 A. Leisos,155 A. G. Leister,177 M. A. L. Leite,24d R. Leitner,129 D. Lellouch,173 B. Lemmer,54 K. J. C. Leney,78 T. Lenz,21 G. Lenzen,176 B. Lenzi,30 R. Leone,7 S. Leone,124a,124b C. Leonidopoulos,46 S. Leontsinis,10 C. Leroy,95 C. G. Lester,28 M. Levchenko,123 J. Levêque,5 D. Levin,89 L. J. Levinson,173 M. Levy,18 A. Lewis,120 A. M. Leyko,21 M. Leyton,41 B. Li,33b,w B. Li,85 H. Li,149 H. L. Li,31 L. Li,45 L. Li,33e S. Li,45 Y. Li,33c,x Z. Liang,138 H. Liao,34 B. Liberti,134a P. Lichard,30 K. Lie,166 J. Liebal,21 W. Liebig,14 C. Limbach,21 A. Limosani,151 S. C. Lin,152,y T. H. Lin,83 F. Linde,107 B. E. Lindquist,149 J. T. Linnemann,90 E. Lipeles,122 A. Lipniacka,14 M. Lisovyi,42 T. M. Liss,166 D. Lissauer,25 A. Lister,169 A. M. Litke,138 B. Liu,152 D. Liu,152 J. Liu,85 J. B. Liu,33b K. Liu,33b,z L. Liu,89 M. Liu,45 M. Liu,33b Y. Liu,33b M. Livan,121a,121b A. Lleres,55 J. Llorente Merino,82 S. L. Lloyd,76 F. Lo Sterzo,152 E. Lobodzinska,42 P. Loch,7 W. S. Lockman,138 F. K. Loebinger,84 A. E. Loevschall-Jensen,36 A. Loginov,177 T. Lohse,16 K. Lohwasser,42 M. Lokajicek,127 B. A. Long,22 J. D. Long,89 R. E. Long,72 K. A. Looper,111 L. Lopes,126a D. Lopez Mateos,57 B. Lopez Paredes,140 I. Lopez Paz,12 J. Lorenz,100 N. Lorenzo Martinez,61 M. Losada,163 P. Loscutoff,15 P. J. Lösel,100 X. Lou,33a A. Lounis,117 J. Love,6 P. A. Love,72 F. Lu,33a N. Lu,89 H. J. Lubatti,139 C. Luci,133a,133b A. Lucotte,55 F. Luehring,61 W. Lukas,62 L. Luminari,133a O. Lundberg,147a,147b B. Lund-Jensen,148 M. Lungwitz,83 D. Lynn,25 R. Lysak,127 E. Lytken,81 H. Ma,25 L. L. Ma,33d G. Maccarrone,47 A. Macchiolo,101 J. Machado Miguens,126a,126b D. Macina,30 D. Madaffari,85 R. Madar,34 H. J. Maddocks,72 W. F. Mader,44 A. Madsen,167 T. Maeno,25 A. Maevskiy,99 E. Magradze,54 K. Mahboubi,48 J. Mahlstedt,107 S. Mahmoud,74 C. Maiani,137 C. Maidantchik,24a A. A. Maier,101 T. Maier,100 A. Maio,126a,126b,126d S. Majewski,116 Y. Makida,66 N. Makovec,117 B. Malaescu,80 Pa. Malecki,39 V. P. Maleev,123 F. Malek,55 U. Mallik,63 D. Malon,6 C. Malone,144 S. Maltezos,10

121801-10 week ending PRL 114, 121801 (2015) PHYSICAL REVIEW LETTERS 27 MARCH 2015

V. M. Malyshev,109 S. Malyukov,30 J. Mamuzic,42 B. Mandelli,30 L. Mandelli,91a I. Mandić,75 R. Mandrysch,63 J. Maneira,126a,126b A. Manfredini,101 L. Manhaes de Andrade Filho,24b J. Manjarres Ramos,160b A. Mann,100 P. M. Manning,138 A. Manousakis-Katsikakis,9 B. Mansoulie,137 R. Mantifel,87 M. Mantoani,54 L. Mapelli,30 L. March,146c G. Marchiori,80 M. Marcisovsky,127 C. P. Marino,170 M. Marjanovic,13 F. Marroquim,24a S. P. Marsden,84 Z. Marshall,15 L. F. Marti,17 S. Marti-Garcia,168 B. Martin,90 T. A. Martin,171 V. J. Martin,46 B. Martin dit Latour,14 H. Martinez,137 M. Martinez,12,o S. Martin-Haugh,131 A. C. Martyniuk,78 M. Marx,139 F. Marzano,133a A. Marzin,30 L. Masetti,83 T. Mashimo,156 R. Mashinistov,96 J. Masik,84 A. L. Maslennikov,109,d I. Massa,20a,20b L. Massa,20a,20b N. Massol,5 P. Mastrandrea,149 A. Mastroberardino,37a,37b T. Masubuchi,156 P. Mättig,176 J. Mattmann,83 J. Maurer,26a S. J. Maxfield,74 D. A. Maximov,109,d R. Mazini,152 S. M. Mazza,91a,91b L. Mazzaferro,134a,134b G. Mc Goldrick,159 S. P. Mc Kee,89 A. McCarn,89 R. L. McCarthy,149 T. G. McCarthy,29 N. A. McCubbin,131 K. W. McFarlane,56,a J. A. Mcfayden,78 G. Mchedlidze,54 S. J. McMahon,131 R. A. McPherson,170,k J. Mechnich,107 M. Medinnis,42 S. Meehan,146a S. Mehlhase,100 A. Mehta,74 K. Meier,58a C. Meineck,100 B. Meirose,41 C. Melachrinos,31 B. R. Mellado Garcia,146c F. Meloni,17 A. Mengarelli,20a,20b S. Menke,101 E. Meoni,162 K. M. Mercurio,57 S. Mergelmeyer,21 N. Meric,137 P. Mermod,49 L. Merola,104a,104b C. Meroni,91a F. S. Merritt,31 H. Merritt,111 A. Messina,30,aa J. Metcalfe,25 A. S. Mete,164 C. Meyer,83 C. Meyer,122 J-P. Meyer,137 J. Meyer,107 R. P. Middleton,131 S. Migas,74 S. Miglioranzi,165a,165c L. Mijović,21 G. Mikenberg,173 M. Mikestikova,127 M. Mikuž,75 A. Milic,30 D. W. Miller,31 C. Mills,46 A. Milov,173 D. A. Milstead,147a,147b A. A. Minaenko,130 Y. Minami,156 I. A. Minashvili,65 A. I. Mincer,110 B. Mindur,38a M. Mineev,65 Y. Ming,174 L. M. Mir,12 G. Mirabelli,133a T. Mitani,172 J. Mitrevski,100 V. A. Mitsou,168 A. Miucci,49 P. S. Miyagawa,140 J. U. Mjörnmark,81 T. Moa,147a,147b K. Mochizuki,85 S. Mohapatra,35 W. Mohr,48 S. Molander,147a,147b R. Moles-Valls,168 K. Mönig,42 C. Monini,55 J. Monk,36 E. Monnier,85 J. Montejo Berlingen,12 F. Monticelli,71 S. Monzani,133a,133b R. W. Moore,3 N. Morange,117 D. Moreno,163 M. Moreno Llácer,54 P. Morettini,50a M. Morgenstern,44 M. Morii,57 V. Morisbak,119 S. Moritz,83 A. K. Morley,148 G. Mornacchi,30 J. D. Morris,76 A. Morton,53 L. Morvaj,103 H. G. Moser,101 M. Mosidze,51b J. Moss,111 K. Motohashi,158 R. Mount,144 E. Mountricha,25 S. V. Mouraviev,96,a E. J. W. Moyse,86 S. Muanza,85 R. D. Mudd,18 F. Mueller,101 J. Mueller,125 K. Mueller,21 R. S. P. Mueller,100 T. Mueller,28 D. Muenstermann,49 P. Mullen,53 Y. Munwes,154 J. A. Murillo Quijada,18 W. J. Murray,171,131 H. Musheghyan,54 E. Musto,153 A. G. Myagkov,130,bb M. Myska,128 O. Nackenhorst,54 J. Nadal,54 K. Nagai,120 R. Nagai,158 Y. Nagai,85 K. Nagano,66 A. Nagarkar,111 Y. Nagasaka,59 K. Nagata,161 M. Nagel,101 E. Nagy,85 A. M. Nairz,30 Y. Nakahama,30 K. Nakamura,66 T. Nakamura,156 I. Nakano,112 H. Namasivayam,41 G. Nanava,21 R. F. Naranjo Garcia,42 R. Narayan,58b T. Nattermann,21 T. Naumann,42 G. Navarro,163 R. Nayyar,7 H. A. Neal,89 P. Yu. Nechaeva,96 T. J. Neep,84 P. D. Nef,144 A. Negri,121a,121b M. Negrini,20a S. Nektarijevic,106 C. Nellist,117 A. Nelson,164 S. Nemecek,127 P. Nemethy,110 A. A. Nepomuceno,24a M. Nessi,30,cc M. S. Neubauer,166 M. Neumann,176 R. M. Neves,110 P. Nevski,25 P. R. Newman,18 D. H. Nguyen,6 R. B. Nickerson,120 R. Nicolaidou,137 B. Nicquevert,30 J. Nielsen,138 N. Nikiforou,35 A. Nikiforov,16 V. Nikolaenko,130,bb I. Nikolic-Audit,80 K. Nikolopoulos,18 P. Nilsson,25 Y. Ninomiya,156 A. Nisati,133a R. Nisius,101 T. Nobe,158 M. Nomachi,118 I. Nomidis,29 T. Nooney,76 S. Norberg,113 M. Nordberg,30 O. Novgorodova,44 S. Nowak,101 M. Nozaki,66 L. Nozka,115 K. Ntekas,10 G. Nunes Hanninger,88 T. Nunnemann,100 E. Nurse,78 F. Nuti,88 B. J. O’Brien,46 F. O’grady,7 D. C. O’Neil,143 V. O’Shea,53 F. G. Oakham,29,e H. Oberlack,101 T. Obermann,21 J. Ocariz,80 A. Ochi,67 I. Ochoa,78 S. Oda,70 S. Odaka,66 H. Ogren,61 A. Oh,84 S. H. Oh,45 C. C. Ohm,15 H. Ohman,167 H. Oide,30 W. Okamura,118 H. Okawa,161 Y. Okumura,31 T. Okuyama,156 A. Olariu,26a A. G. Olchevski,65 S. A. Olivares Pino,46 D. Oliveira Damazio,25 E. Oliver Garcia,168 A. Olszewski,39 J. Olszowska,39 A. Onofre,126a,126e P. U. E. Onyisi,31,q C. J. Oram,160a M. J. Oreglia,31 Y. Oren,154 D. Orestano,135a,135b N. Orlando,155 C. Oropeza Barrera,53 R. S. Orr,159 B. Osculati,50a,50b R. Ospanov,84 G. Otero y Garzon,27 H. Otono,70 M. Ouchrif,136d E. A. Ouellette,170 F. Ould-Saada,119 A. Ouraou,137 K. P. Oussoren,107 Q. Ouyang,33a A. Ovcharova,15 M. Owen,53 V. E. Ozcan,19a N. Ozturk,8 K. Pachal,120 A. Pacheco Pages,12 C. Padilla Aranda,12 M. Pagáčová,48 S. Pagan Griso,15 E. Paganis,140 C. Pahl,101 F. Paige,25 P. Pais,86 K. Pajchel,119 G. Palacino,160b S. Palestini,30 M. Palka,38b D. Pallin,34 A. Palma,126a,126b Y. B. Pan,174 E. Panagiotopoulou,10 C. E. Pandini,80 J. G. Panduro Vazquez,77 P. Pani,147a,147b N. Panikashvili,89 S. Panitkin,25 L. Paolozzi,134a,134b Th. D. Papadopoulou,10 K. Papageorgiou,155 A. Paramonov,6 D. Paredes Hernandez,155 M. A. Parker,28 K. A. Parker,140 F. Parodi,50a,50b J. A. Parsons,35 U. Parzefall,48 E. Pasqualucci,133a S. Passaggio,50a F. Pastore,135a,135b,a Fr. Pastore,77 G. Pásztor,29 S. Pataraia,176 N. D. Patel,151 J. R. Pater,84 T. Pauly,30 J. Pearce,170 L. E. Pedersen,36 M. Pedersen,119 S. Pedraza Lopez,168 R. Pedro,126a,126b S. V. Peleganchuk,109 D. Pelikan,167 H. Peng,33b B. Penning,31 J. Penwell,61 D. V. Perepelitsa,25 E. Perez Codina,160a M. T. Pérez García-Estañ,168 L. Perini,91a,91b

121801-11 week ending PRL 114, 121801 (2015) PHYSICAL REVIEW LETTERS 27 MARCH 2015

H. Pernegger,30 S. Perrella,104a,104b R. Peschke,42 V. D. Peshekhonov,65 K. Peters,30 R. F. Y. Peters,84 B. A. Petersen,30 T. C. Petersen,36 E. Petit,42 A. Petridis,147a,147b C. Petridou,155 E. Petrolo,133a F. Petrucci,135a,135b N. E. Pettersson,158 R. Pezoa,32b P. W. Phillips,131 G. Piacquadio,144 E. Pianori,171 A. Picazio,49 E. Piccaro,76 M. Piccinini,20a,20b M. A. Pickering,120 R. Piegaia,27 D. T. Pignotti,111 J. E. Pilcher,31 A. D. Pilkington,78 J. Pina,126a,126b,126d M. Pinamonti,165a,165c,dd J. L. Pinfold,3 A. Pingel,36 B. Pinto,126a S. Pires,80 M. Pitt,173 C. Pizio,91a,91b L. Plazak,145a M.-A. Pleier,25 V. Pleskot,129 E. Plotnikova,65 P. Plucinski,147a,147b D. Pluth,64 R. Poettgen,83 L. Poggioli,117 D. Pohl,21 G. Polesello,121a A. Policicchio,37a,37b R. Polifka,159 A. Polini,20a C. S. Pollard,53 V. Polychronakos,25 K. Pommès,30 L. Pontecorvo,133a B. G. Pope,90 G. A. Popeneciu,26b D. S. Popovic,13 A. Poppleton,30 S. Pospisil,128 K. Potamianos,15 I. N. Potrap,65 C. J. Potter,150 C. T. Potter,116 G. Poulard,30 J. Poveda,30 V. Pozdnyakov,65 P. Pralavorio,85 A. Pranko,15 S. Prasad,30 S. Prell,64 D. Price,84 J. Price,74 L. E. Price,6 M. Primavera,73a S. Prince,87 M. Proissl,46 K. Prokofiev,60c F. Prokoshin,32b E. Protopapadaki,137 S. Protopopescu,25 J. Proudfoot,6 M. Przybycien,38a E. Ptacek,116 D. Puddu,135a,135b E. Pueschel,86 D. Puldon,149 M. Purohit,25,ee P. Puzo,117 J. Qian,89 G. Qin,53 Y. Qin,84 A. Quadt,54 D. R. Quarrie,15 W. B. Quayle,165a,165b M. Queitsch-Maitland,84 D. Quilty,53 A. Qureshi,160b V. Radeka,25 V. Radescu,42 S. K. Radhakrishnan,149 P. Radloff,116 P. Rados,88 F. Ragusa,91a,91b G. Rahal,179 S. Rajagopalan,25 M. Rammensee,30 C. Rangel-Smith,167 F. Rauscher,100 S. Rave,83 T. C. Rave,48 T. Ravenscroft,53 M. Raymond,30 A. L. Read,119 N. P. Readioff,74 D. M. Rebuzzi,121a,121b A. Redelbach,175 G. Redlinger,25 R. Reece,138 K. Reeves,41 L. Rehnisch,16 H. Reisin,27 M. Relich,164 C. Rembser,30 H. Ren,33a A. Renaud,117 M. Rescigno,133a S. Resconi,91a O. L. Rezanova,109,d P. Reznicek,129 R. Rezvani,95 R. Richter,101 E. Richter-Was,38b M. Ridel,80 P. Rieck,16 C. J. Riegel,176 J. Rieger,54 M. Rijssenbeek,149 A. Rimoldi,121a,121b L. Rinaldi,20a E. Ritsch,62 I. Riu,12 F. Rizatdinova,114 E. Rizvi,76 S. H. Robertson,87,k A. Robichaud-Veronneau,87 D. Robinson,28 J. E. M. Robinson,84 A. Robson,53 C. Roda,124a,124b L. Rodrigues,30 S. Roe,30 O. Røhne,119 S. Rolli,162 A. Romaniouk,98 M. Romano,20a,20b S. M. Romano Saez,34 E. Romero Adam,168 N. Rompotis,139 M. Ronzani,48 L. Roos,80 E. Ros,168 S. Rosati,133a K. Rosbach,48 P. Rose,138 P. L. Rosendahl,14 O. Rosenthal,142 V. Rossetti,147a,147b E. Rossi,104a,104b L. P. Rossi,50a R. Rosten,139 M. Rotaru,26a I. Roth,173 J. Rothberg,139 D. Rousseau,117 C. R. Royon,137 A. Rozanov,85 Y. Rozen,153 X. Ruan,146c F. Rubbo,144 I. Rubinskiy,42 V. I. Rud,99 C. Rudolph,44 M. S. Rudolph,159 F. Rühr,48 A. Ruiz-Martinez,30 Z. Rurikova,48 N. A. Rusakovich,65 A. Ruschke,100 H. L. Russell,139 J. P. Rutherfoord,7 N. Ruthmann,48 Y. F. Ryabov,123 M. Rybar,129 G. Rybkin,117 N. C. Ryder,120 A. F. Saavedra,151 G. Sabato,107 S. Sacerdoti,27 A. Saddique,3 H. F-W. Sadrozinski,138 R. Sadykov,65 F. Safai Tehrani,133a M. Saimpert,137 H. Sakamoto,156 Y. Sakurai,172 G. Salamanna,135a,135b A. Salamon,134a M. Saleem,113 D. Salek,107 P. H. Sales De Bruin,139 D. Salihagic,101 A. Salnikov,144 J. Salt,168 D. Salvatore,37a,37b F. Salvatore,150 A. Salvucci,106 A. Salzburger,30 D. Sampsonidis,155 A. Sanchez,104a,104b J. Sánchez,168 V. Sanchez Martinez,168 H. Sandaker,14 R. L. Sandbach,76 H. G. Sander,83 M. P. Sanders,100 M. Sandhoff,176 C. Sandoval,163 R. Sandstroem,101 D. P. C. Sankey,131 A. Sansoni,47 C. Santoni,34 R. Santonico,134a,134b H. Santos,126a I. Santoyo Castillo,150 K. Sapp,125 A. Sapronov,65 J. G. Saraiva,126a,126d B. Sarrazin,21 O. Sasaki,66 Y. Sasaki,156 K. Sato,161 G. Sauvage,5,a E. Sauvan,5 G. Savage,77 P. Savard,159,e C. Sawyer,120 L. Sawyer,79,n D. H. Saxon,53 J. Saxon,31 C. Sbarra,20a A. Sbrizzi,20a,20b T. Scanlon,78 D. A. Scannicchio,164 M. Scarcella,151 V. Scarfone,37a,37b J. Schaarschmidt,173 P. Schacht,101 D. Schaefer,30 R. Schaefer,42 J. Schaeffer,83 S. Schaepe,21 S. Schaetzel,58b U. Schäfer,83 A. C. Schaffer,117 D. Schaile,100 R. D. Schamberger,149 V. Scharf,58a V. A. Schegelsky,123 D. Scheirich,129 M. Schernau,164 C. Schiavi,50a,50b J. Schieck,100 C. Schillo,48 M. Schioppa,37a,37b S. Schlenker,30 E. Schmidt,48 K. Schmieden,30 C. Schmitt,83 S. Schmitt,58b B. Schneider,160a Y. J. Schnellbach,74 U. Schnoor,44 L. Schoeffel,137 A. Schoening,58b B. D. Schoenrock,90 A. L. S. Schorlemmer,54 M. Schott,83 D. Schouten,160a J. Schovancova,8 S. Schramm,159 M. Schreyer,175 C. Schroeder,83 N. Schuh,83 M. J. Schultens,21 H.-C. Schultz-Coulon,58a H. Schulz,16 M. Schumacher,48 B. A. Schumm,138 Ph. Schune,137 C. Schwanenberger,84 A. Schwartzman,144 T. A. Schwarz,89 Ph. Schwegler,101 Ph. Schwemling,137 R. Schwienhorst,90 J. Schwindling,137 T. Schwindt,21 M. Schwoerer,5 F. G. Sciacca,17 E. Scifo,117 G. Sciolla,23 F. Scuri,124a,124b F. Scutti,21 J. Searcy,89 G. Sedov,42 E. Sedykh,123 P. Seema,21 S. C. Seidel,105 A. Seiden,138 F. Seifert,128 J. M. Seixas,24a G. Sekhniaidze,104a S. J. Sekula,40 K. E. Selbach,46 D. M. Seliverstov,123,a N. Semprini-Cesari,20a,20b C. Serfon,30 L. Serin,117 L. Serkin,54 T. Serre,85 R. Seuster,160a H. Severini,113 T. Sfiligoj,75 F. Sforza,101 A. Sfyrla,30 E. Shabalina,54 M. Shamim,116 L. Y. Shan,33a R. Shang,166 J. T. Shank,22 M. Shapiro,15 P. B. Shatalov,97 K. Shaw,165a,165b A. Shcherbakova,147a,147b C. Y. Shehu,150 P. Sherwood,78 L. Shi,152,ff S. Shimizu,67 C. O. Shimmin,164 M. Shimojima,102 M. Shiyakova,65 A. Shmeleva,96 D. Shoaleh Saadi,95 M. J. Shochet,31 S. Shojaii,91a,91b S. Shrestha,111 E. Shulga,98 M. A. Shupe,7 S. Shushkevich,42 P. Sicho,127

121801-12 week ending PRL 114, 121801 (2015) PHYSICAL REVIEW LETTERS 27 MARCH 2015

O. Sidiropoulou,175 D. Sidorov,114 A. Sidoti,20a,20b F. Siegert,44 Dj. Sijacki,13 J. Silva,126a,126d Y. Silver,154 D. Silverstein,144 S. B. Silverstein,147a V. Simak,128 O. Simard,5 Lj. Simic,13 S. Simion,117 E. Simioni,83 B. Simmons,78 D. Simon,34 R. Simoniello,91a,91b P. Sinervo,159 N. B. Sinev,116 G. Siragusa,175 A. Sircar,79 A. N. Sisakyan,65,a S. Yu. Sivoklokov,99 J. Sjölin,147a,147b T. B. Sjursen,14 M. B. Skinner,72 H. P. Skottowe,57 P. Skubic,113 M. Slater,18 T. Slavicek,128 M. Slawinska,107 K. Sliwa,162 V. Smakhtin,173 B. H. Smart,46 L. Smestad,14 S. Yu. Smirnov,98 Y. Smirnov,98 L. N. Smirnova,99,gg O. Smirnova,81 K. M. Smith,53 M. Smith,35 M. Smizanska,72 K. Smolek,128 A. A. Snesarev,96 G. Snidero,76 S. Snyder,25 R. Sobie,170,k F. Socher,44 A. Soffer,154 D. A. Soh,152,ff C. A. Solans,30 M. Solar,128 J. Solc,128 E. Yu. Soldatov,98 U. Soldevila,168 A. A. Solodkov,130 A. Soloshenko,65 O. V. Solovyanov,130 V. Solovyev,123 P. Sommer,48 H. Y. Song,33b N. Soni,1 A. Sood,15 A. Sopczak,128 B. Sopko,128 V. Sopko,128 V. Sorin,12 D. Sosa,58b M. Sosebee,8 C. L. Sotiropoulou,155 R. Soualah,165a,165c P. Soueid,95 A. M. Soukharev,109,d D. South,42 S. Spagnolo,73a,73b F. Spanò,77 W. R. Spearman,57 F. Spettel,101 R. Spighi,20a G. Spigo,30 L. A. Spiller,88 M. Spousta,129 T. Spreitzer,159 R. D. St. Denis,53,a S. Staerz,44 J. Stahlman,122 R. Stamen,58a S. Stamm,16 E. Stanecka,39 C. Stanescu,135a M. Stanescu-Bellu,42 M. M. Stanitzki,42 S. Stapnes,119 E. A. Starchenko,130 J. Stark,55 P. Staroba,127 P. Starovoitov,42 R. Staszewski,39 P. Stavina,145a,a P. Steinberg,25 B. Stelzer,143 H. J. Stelzer,30 O. Stelzer-Chilton,160a H. Stenzel,52 S. Stern,101 G. A. Stewart,53 J. A. Stillings,21 M. C. Stockton,87 M. Stoebe,87 G. Stoicea,26a P. Stolte,54 S. Stonjek,101 A. R. Stradling,8 A. Straessner,44 M. E. Stramaglia,17 J. Strandberg,148 S. Strandberg,147a,147b A. Strandlie,119 E. Strauss,144 M. Strauss,113 P. Strizenec,145b R. Ströhmer,175 D. M. Strom,116 R. Stroynowski,40 A. Strubig,106 S. A. Stucci,17 B. Stugu,14 N. A. Styles,42 D. Su,144 J. Su,125 R. Subramaniam,79 A. Succurro,12 Y. Sugaya,118 C. Suhr,108 M. Suk,128 V. V. Sulin,96 S. Sultansoy,4c T. Sumida,68 S. Sun,57 X. Sun,33a J. E. Sundermann,48 K. Suruliz,150 G. Susinno,37a,37b M. R. Sutton,150 Y. Suzuki,66 M. Svatos,127 S. Swedish,169 M. Swiatlowski,144 I. Sykora,145a T. Sykora,129 D. Ta,90 C. Taccini,135a,135b K. Tackmann,42 J. Taenzer,159 A. Taffard,164 R. Tafirout,160a N. Taiblum,154 H. Takai,25 R. Takashima,69 H. Takeda,67 T. Takeshita,141 Y. Takubo,66 M. Talby,85 A. A. Talyshev,109,d J. Y. C. Tam,175 K. G. Tan,88 J. Tanaka,156 R. Tanaka,117 S. Tanaka,132 S. Tanaka,66 A. J. Tanasijczuk,143 B. B. Tannenwald,111 N. Tannoury,21 S. Tapprogge,83 S. Tarem,153 F. Tarrade,29 G. F. Tartarelli,91a P. Tas,129 M. Tasevsky,127 T. Tashiro,68 E. Tassi,37a,37b A. Tavares Delgado,126a,126b Y. Tayalati,136d F. E. Taylor,94 G. N. Taylor,88 W. Taylor,160b F. A. Teischinger,30 M. Teixeira Dias Castanheira,76 P. Teixeira-Dias,77 K. K. Temming,48 H. Ten Kate,30 P. K. Teng,152 J. J. Teoh,118 F. Tepel,176 S. Terada,66 K. Terashi,156 J. Terron,82 S. Terzo,101 M. Testa,47 R. J. Teuscher,159,k J. Therhaag,21 T. Theveneaux-Pelzer,34 J. P. Thomas,18 J. Thomas-Wilsker,77 E. N. Thompson,35 P. D. Thompson,18 R. J. Thompson,84 A. S. Thompson,53 L. A. Thomsen,36 E. Thomson,122 M. Thomson,28 W. M. Thong,88 R. P. Thun,89,a F. Tian,35 M. J. Tibbetts,15 R. E. Ticse Torres,85 V. O. Tikhomirov,96,hh Yu. A. Tikhonov,109,d S. Timoshenko,98 E. Tiouchichine,85 P. Tipton,177 S. Tisserant,85 T. Todorov,5,a S. Todorova-Nova,129 J. Tojo,70 S. Tokár,145a K. Tokushuku,66 K. Tollefson,90 E. Tolley,57 L. Tomlinson,84 M. Tomoto,103 L. Tompkins,144,ii K. Toms,105 N. D. Topilin,65 E. Torrence,116 H. Torres,143 E. Torró Pastor,168 J. Toth,85,jj F. Touchard,85 D. R. Tovey,140 H. L. Tran,117 T. Trefzger,175 L. Tremblet,30 A. Tricoli,30 I. M. Trigger,160a S. Trincaz-Duvoid,80 M. F. Tripiana,12 W. Trischuk,159 B. Trocmé,55 C. Troncon,91a M. Trottier-McDonald,15 M. Trovatelli,135a,135b P. True,90 M. Trzebinski,39 A. Trzupek,39 C. Tsarouchas,30 J. C-L. Tseng,120 P. V. Tsiareshka,92 D. Tsionou,137 G. Tsipolitis,10 N. Tsirintanis,9 S. Tsiskaridze,12 V. Tsiskaridze,48 E. G. Tskhadadze,51a I. I. Tsukerman,97 V. Tsulaia,15 S. Tsuno,66 D. Tsybychev,149 A. Tudorache,26a V. Tudorache,26a A. N. Tuna,122 S. A. Tupputi,20a,20b S. Turchikhin,99,gg D. Turecek,128 I. Turk Cakir,4b R. Turra,91a,91b A. J. Turvey,40 P. M. Tuts,35 A. Tykhonov,49 M. Tylmad,147a,147b M. Tyndel,131 I. Ueda,156 R. Ueno,29 M. Ughetto,85 M. Ugland,14 M. Uhlenbrock,21 F. Ukegawa,161 G. Unal,30 A. Undrus,25 G. Unel,164 F. C. Ungaro,48 Y. Unno,66 C. Unverdorben,100 J. Urban,145b P. Urquijo,88 P. Urrejola,83 G. Usai,8 A. Usanova,62 L. Vacavant,85 V. Vacek,128 B. Vachon,87 N. Valencic,107 S. Valentinetti,20a,20b A. Valero,168 L. Valery,12 S. Valkar,129 E. Valladolid Gallego,168 S. Vallecorsa,49 J. A. Valls Ferrer,168 W. Van Den Wollenberg,107 P. C. Van Der Deijl,107 R. van der Geer,107 H. van der Graaf,107 R. Van Der Leeuw,107 N. van Eldik,30 P. van Gemmeren,6 J. Van Nieuwkoop,143 I. van Vulpen,107 M. C. van Woerden,30 M. Vanadia,133a,133b W. Vandelli,30 R. Vanguri,122 A. Vaniachine,6 F. Vannucci,80 G. Vardanyan,178 R. Vari,133a E. W. Varnes,7 T. Varol,40 D. Varouchas,80 A. Vartapetian,8 K. E. Varvell,151 F. Vazeille,34 T. Vazquez Schroeder,54 J. Veatch,7 F. Veloso,126a,126c T. Velz,21 S. Veneziano,133a A. Ventura,73a,73b D. Ventura,86 M. Venturi,170 N. Venturi,159 A. Venturini,23 V. Vercesi,121a M. Verducci,133a,133b W. Verkerke,107 J. C. Vermeulen,107 A. Vest,44 M. C. Vetterli,143,e O. Viazlo,81 I. Vichou,166 T. Vickey,146c,kk O. E. Vickey Boeriu,146c G. H. A. Viehhauser,120 S. Viel,15 R. Vigne,30 M. Villa,20a,20b M. Villaplana Perez,91a,91b E. Vilucchi,47 M. G. Vincter,29 V. B. Vinogradov,65 J. Virzi,15 I. Vivarelli,150 F. Vives Vaque,3

121801-13 week ending PRL 114, 121801 (2015) PHYSICAL REVIEW LETTERS 27 MARCH 2015

S. Vlachos,10 D. Vladoiu,100 M. Vlasak,128 M. Vogel,32a P. Vokac,128 G. Volpi,124a,124b M. Volpi,88 H. von der Schmitt,101 H. von Radziewski,48 E. von Toerne,21 V. Vorobel,129 K. Vorobev,98 M. Vos,168 R. Voss,30 J. H. Vossebeld,74 N. Vranjes,13 M. Vranjes Milosavljevic,13 V. Vrba,127 M. Vreeswijk,107 R. Vuillermet,30 I. Vukotic,31 Z. Vykydal,128 P. Wagner,21 W. Wagner,176 H. Wahlberg,71 S. Wahrmund,44 J. Wakabayashi,103 J. Walder,72 R. Walker,100 W. Walkowiak,142 C. Wang,33c F. Wang,174 H. Wang,15 H. Wang,40 J. Wang,42 J. Wang,33a K. Wang,87 R. Wang,105 S. M. Wang,152 T. Wang,21 X. Wang,177 C. Wanotayaroj,116 A. Warburton,87 C. P. Ward,28 D. R. Wardrope,78 M. Warsinsky,48 A. Washbrook,46 C. Wasicki,42 P. M. Watkins,18 A. T. Watson,18 I. J. Watson,151 M. F. Watson,18 G. Watts,139 S. Watts,84 B. M. Waugh,78 S. Webb,84 M. S. Weber,17 S. W. Weber,175 J. S. Webster,31 A. R. Weidberg,120 B. Weinert,61 J. Weingarten,54 C. Weiser,48 H. Weits,107 P. S. Wells,30 T. Wenaus,25 D. Wendland,16 T. Wengler,30 S. Wenig,30 N. Wermes,21 M. Werner,48 P. Werner,30 M. Wessels,58a J. Wetter,162 K. Whalen,29 A. M. Wharton,72 A. White,8 M. J. White,1 R. White,32b S. White,124a,124b D. Whiteson,164 D. Wicke,176 F. J. Wickens,131 W. Wiedenmann,174 M. Wielers,131 P. Wienemann,21 C. Wiglesworth,36 L. A. M. Wiik-Fuchs,21 A. Wildauer,101 H. G. Wilkens,30 H. H. Williams,122 S. Williams,107 C. Willis,90 S. Willocq,86 A. Wilson,89 J. A. Wilson,18 I. Wingerter-Seez,5 F. Winklmeier,116 B. T. Winter,21 M. Wittgen,144 J. Wittkowski,100 S. J. Wollstadt,83 M. W. Wolter,39 H. Wolters,126a,126c B. K. Wosiek,39 J. Wotschack,30 M. J. Woudstra,84 K. W. Wozniak,39 M. Wu,55 S. L. Wu,174 X. Wu,49 Y. Wu, 89 T. R. Wyatt,84 B. M. Wynne,46 S. Xella,36 D. Xu,33a L. Xu,33b,ll B. Yabsley,151 S. Yacoob,146b,mm R. Yakabe,67 M. Yamada,66 Y. Yamaguchi,118 A. Yamamoto,66 S. Yamamoto,156 T. Yamanaka,156 K. Yamauchi,103 Y. Yamazaki,67 Z. Yan,22 H. Yang,33e H. Yang,174 Y. Yang,152 S. Yanush,93 L. Yao,33a W-M. Yao,15 Y. Yasu,66 E. Yatsenko,42 K. H. Yau Wong,21 J. Ye,40 S. Ye,25 I. Yeletskikh,65 A. L. Yen,57 E. Yildirim,42 K. Yorita,172 R. Yoshida,6 K. Yoshihara,122 C. Young,144 C. J. S. Young,30 S. Youssef,22 D. R. Yu,15 J. Yu,8 J. M. Yu,89 J. Yu,114 L. Yuan,67 A. Yurkewicz,108 I. Yusuff,28,nn B. Zabinski,39 R. Zaidan,63 A. M. Zaitsev,130,bb A. Zaman,149 S. Zambito,23 L. Zanello,133a,133b D. Zanzi,88 C. Zeitnitz,176 M. Zeman,128 A. Zemla,38a K. Zengel,23 O. Zenin,130 T. Ženiš,145a D. Zerwas,117 D. Zhang,89 F. Zhang,174 J. Zhang,6 L. Zhang,152 R. Zhang,33b X. Zhang,33d Z. Zhang,117 X. Zhao,40 Y. Zhao,33d,117 Z. Zhao,33b A. Zhemchugov,65 J. Zhong,120 B. Zhou,89 C. Zhou,45 L. Zhou,35 L. Zhou,40 N. Zhou,164 C. G. Zhu,33d H. Zhu,33a J. Zhu,89 Y. Zhu,33b X. Zhuang,33a K. Zhukov,96 A. Zibell,175 D. Zieminska,61 N. I. Zimine,65 C. Zimmermann,83 R. Zimmermann,21 S. Zimmermann,48 Z. Zinonos,54 M. Ziolkowski,142 L. Živković,13 G. Zobernig,174 A. Zoccoli,20a,20b M. zur Nedden,16 G. Zurzolo,104a,104b and L. Zwalinski30

(ATLAS Collaboration)

1Department of Physics, University of Adelaide, Adelaide, Australia 2Physics Department, SUNY Albany, Albany NY, United States of America 3Department of Physics, University of Alberta, Edmonton AB, Canada 4aDepartment of Physics, Ankara University, Ankara, Turkey 4bIstanbul Aydin University, Istanbul, Turkey 4cDivision of Physics, TOBB University of Economics and Technology, Ankara, Turkey 5LAPP, CNRS/IN2P3 and Université de Savoie, Annecy-le-Vieux, France 6High Energy Physics Division, Argonne National Laboratory, Argonne, IL, United States of America 7Department of Physics, University of Arizona, Tucson, AZ, United States of America 8Department of Physics, The University of Texas at Arlington, Arlington, TX, United States of America 9Physics Department, University of Athens, Athens, Greece 10Physics Department, National Technical University of Athens, Zografou, Greece 11Institute of Physics, Azerbaijan Academy of Sciences, Baku, Azerbaijan 12Institut de Física d’Altes Energies and Departament de Física de la Universitat Autònoma de Barcelona, Barcelona, Spain 13Institute of Physics, University of Belgrade, Belgrade, Serbia 14Department for Physics and Technology, University of Bergen, Bergen, Norway 15Physics Division, Lawrence Berkeley National Laboratory and University of California, Berkeley, CA, United States of America 16Department of Physics, Humboldt University, Berlin, Germany 17Albert Einstein Center for Fundamental Physics and Laboratory for High Energy Physics, University of Bern, Bern, Switzerland 18School of Physics and Astronomy, University of Birmingham, Birmingham, United Kingdom 19aDepartment of Physics, Bogazici University, Istanbul, Turkey 19bDepartment of Physics, Dogus University, Istanbul, Turkey 19cDepartment of Physics Engineering, Gaziantep University, Gaziantep, Turkey 20aINFN Sezione di Bologna, Italy 20bDipartimento di Fisica e Astronomia, Università di Bologna, Bologna, Italy

121801-14 week ending PRL 114, 121801 (2015) PHYSICAL REVIEW LETTERS 27 MARCH 2015

21Physikalisches Institut, University of Bonn, Bonn, Germany 22Department of Physics, Boston University, Boston, MA, United States of America 23Department of Physics, Brandeis University, Waltham, MA, United States of America 24aUniversidade Federal do Rio De Janeiro COPPE/EE/IF, Rio de Janeiro, Brazil 24bElectrical Circuits Department, Federal University of Juiz de Fora (UFJF), Juiz de Fora, Brazil 24cFederal University of Sao Joao del Rei (UFSJ), Sao Joao del Rei, Brazil 24dInstituto de Fisica, Universidade de Sao Paulo, Sao Paulo, Brazil 25Physics Department, Brookhaven National Laboratory, Upton, NY, United States of America 26aNational Institute of Physics and Nuclear Engineering, Bucharest, Romania 26bNational Institute for Research and Development of Isotopic and Molecular Technologies, Physics Department, Cluj Napoca, Romania 26cUniversity Politehnica Bucharest, Bucharest, Romania 26dWest University in Timisoara, Timisoara, Romania 27Departamento de Física, Universidad de Buenos Aires, Buenos Aires, Argentina 28Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom 29Department of Physics, Carleton University, Ottawa, ON, Canada 30CERN, Geneva, Switzerland 31Enrico Fermi Institute, University of Chicago, Chicago, IL, United States of America 32aDepartamento de Física, Pontificia Universidad Católica de Chile, Santiago, Chile 32bDepartamento de Física, Universidad Técnica Federico Santa María, Valparaíso, Chile 33aInstitute of High Energy Physics, Chinese Academy of Sciences, Beijing, China 33bDepartment of Modern Physics, University of Science and Technology of China, Anhui, China 33cDepartment of Physics, Nanjing University, Jiangsu, China 33dSchool of Physics, Shandong University, Shandong, China 33eDepartment of Physics and Astronomy, Shanghai Key Laboratory for Particle Physics and Cosmology, Shanghai Jiao Tong University, Shanghai, China 33fPhysics Department, Tsinghua University, Beijing 100084, China 34Laboratoire de Physique Corpusculaire, Clermont Université and Université Blaise Pascal and CNRS/IN2P3, Clermont-Ferrand, France 35Nevis Laboratory, Columbia University, Irvington, NY, United States of America 36Niels Bohr Institute, University of Copenhagen, Kobenhavn, Denmark 37aINFN Gruppo Collegato di Cosenza, Laboratori Nazionali di Frascati, Italy 37bDipartimento di Fisica, Università della Calabria, Rende, Italy 38aAGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Krakow, Poland 38bMarian Smoluchowski Institute of Physics, Jagiellonian University, Krakow, Poland 39The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Poland 40Physics Department, Southern Methodist University, Dallas, TX, United States of America 41Physics Department, University of Texas at Dallas, Richardson, TX, United States of America 42DESY, Hamburg and Zeuthen, Germany 43Institut für Experimentelle Physik IV, Technische Universität Dortmund, Dortmund, Germany 44Institut für Kern- und Teilchenphysik, Technische Universität Dresden, Dresden, Germany 45Department of Physics, Duke University, Durham NC, United States of America 46SUPA - School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom 47INFN Laboratori Nazionali di Frascati, Frascati, Italy 48Fakultät für Mathematik und Physik, Albert-Ludwigs-Universität, Freiburg, Germany 49Section de Physique, Université de Genève, Geneva, Switzerland 50aINFN Sezione di Genova, Italy 50bDipartimento di Fisica, Università di Genova, Genova, Italy 51aE. Andronikashvili Institute of Physics, Iv. Javakhishvili Tbilisi State University, Tbilisi, Georgia 51bHigh Energy Physics Institute, Tbilisi State University, Tbilisi, Georgia 52II Physikalisches Institut, Justus-Liebig-Universität Giessen, Giessen, Germany 53SUPA - School of Physics and Astronomy, University of Glasgow, Glasgow, United Kingdom 54II Physikalisches Institut, Georg-August-Universität, Göttingen, Germany 55Laboratoire de Physique Subatomique et de Cosmologie, Université Grenoble-Alpes, CNRS/IN2P3, Grenoble, France 56Department of Physics, Hampton University, Hampton, VA, United States of America 57Laboratory for Particle Physics and Cosmology, Harvard University, Cambridge, MA, United States of America 58aKirchhoff-Institut für Physik, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany 58bPhysikalisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany 58cZITI Institut für technische Informatik, Ruprecht-Karls-Universität Heidelberg, Mannheim, Germany 59Faculty of Applied Information Science, Hiroshima Institute of Technology, Hiroshima, Japan

121801-15 week ending PRL 114, 121801 (2015) PHYSICAL REVIEW LETTERS 27 MARCH 2015

60aDepartment of Physics, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China 60bDepartment of Physics, The University of Hong Kong, Hong Kong, China 60cDepartment of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China 61Department of Physics, Indiana University, Bloomington, IN, United States of America 62Institut für Astro- und Teilchenphysik, Leopold-Franzens-Universität, Innsbruck, Austria 63University of Iowa, Iowa City, IA, United States of America 64Department of Physics and Astronomy, Iowa State University, Ames, IA, United States of America 65Joint Institute for Nuclear Research, JINR Dubna, Dubna, Russia 66KEK, High Energy Accelerator Research Organization, Tsukuba, Japan 67Graduate School of Science, Kobe University, Kobe, Japan 68Faculty of Science, Kyoto University, Kyoto, Japan 69Kyoto University of Education, Kyoto, Japan 70Department of Physics, Kyushu University, Fukuoka, Japan 71Instituto de Física La Plata, Universidad Nacional de La Plata and CONICET, La Plata, Argentina 72Physics Department, Lancaster University, Lancaster, United Kingdom 73aINFN Sezione di Lecce, Italy 73bDipartimento di Matematica e Fisica, Università del Salento, Lecce, Italy 74Oliver Lodge Laboratory, University of Liverpool, Liverpool, United Kingdom 75Department of Physics, Jožef Stefan Institute and University of Ljubljana, Ljubljana, Slovenia 76School of Physics and Astronomy, Queen Mary University of London, London, United Kingdom 77Department of Physics, Royal Holloway University of London, Surrey, United Kingdom 78Department of Physics and Astronomy, University College London, London, United Kingdom 79Louisiana Tech University, Ruston, LA, United States of America 80Laboratoire de Physique Nucléaire et de Hautes Energies, UPMC and Université Paris-Diderot and CNRS/IN2P3, Paris, France 81Fysiska institutionen, Lunds universitet, Lund, Sweden 82Departamento de Fisica Teorica C-15, Universidad Autonoma de Madrid, Madrid, Spain 83Institut für Physik, Universität Mainz, Mainz, Germany 84School of Physics and Astronomy, University of Manchester, Manchester, United Kingdom 85CPPM, Aix-Marseille Université and CNRS/IN2P3, Marseille, France 86Department of Physics, University of Massachusetts, Amherst, MA, United States of America 87Department of Physics, McGill University, Montreal QC, Canada 88School of Physics, University of Melbourne, Victoria, Australia 89Department of Physics, The University of Michigan, Ann Arbor, MI, United States of America 90Department of Physics and Astronomy, Michigan State University, East Lansing, MI, United States of America 91aINFN Sezione di Milano, Milano, Italy 91bDipartimento di Fisica, Università di Milano, Milano, Italy 92B.I. Stepanov Institute of Physics, National Academy of Sciences of Belarus, Minsk, Republic of Belarus 93National Scientific and Educational Centre for Particle and High Energy Physics, Minsk, Republic of Belarus 94Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, United States of America 95Group of Particle Physics, University of Montreal, Montreal, QC, Canada 96P.N. Lebedev Institute of Physics, Academy of Sciences, Moscow, Russia 97Institute for Theoretical and Experimental Physics (ITEP), Moscow, Russia 98National Research Nuclear University MEPhI, Moscow, Russia 99D.V. Skobeltsyn Institute of Nuclear Physics, M.V. Lomonosov Moscow State University, Moscow, Russia 100Fakultät für Physik, Ludwig-Maximilians-Universität München, München, Germany 101Max-Planck-Institut für Physik (Werner-Heisenberg-Institut), München, Germany 102Nagasaki Institute of Applied Science, Nagasaki, Japan 103Graduate School of Science and Kobayashi-Maskawa Institute, Nagoya University, Nagoya, Japan 104aINFN Sezione di Napoli, Napoli, Italy 104bDipartimento di Fisica, Università di Napoli, Napoli, Italy 105Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM, United States of America 106Institute for Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen/Nikhef, Nijmegen, Netherlands 107Nikhef National Institute for Subatomic Physics and University of Amsterdam, Amsterdam, Netherlands 108Department of Physics, Northern Illinois University, DeKalb, IL, United States of America 109Budker Institute of Nuclear Physics, SB RAS, Novosibirsk, Russia 110Department of Physics, New York University, New York, NY, United States of America 111Ohio State University, Columbus, OH, United States of America 112Faculty of Science, Okayama University, Okayama, Japan 113Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK, United States of America 114Department of Physics, Oklahoma State University, Stillwater, OK, United States of America

121801-16 week ending PRL 114, 121801 (2015) PHYSICAL REVIEW LETTERS 27 MARCH 2015

115Palacký University, RCPTM, Olomouc, Czech Republic 116Center for High Energy Physics, University of Oregon, Eugene, OR, United States of America 117LAL, Université Paris-Sud and CNRS/IN2P3, Orsay, France 118Graduate School of Science, Osaka University, Osaka, Japan 119Department of Physics, University of Oslo, Oslo, Norway 120Department of Physics, Oxford University, Oxford, United Kingdom 121aINFN Sezione di Pavia, Pavia, Italy 121bDipartimento di Fisica, Università di Pavia, Pavia, Italy 122Department of Physics, University of Pennsylvania, Philadelphia, PA, United States of America 123Petersburg Nuclear Physics Institute, Gatchina, Russia 124aINFN Sezione di Pisa, Pisa, Italy 124bDipartimento di Fisica E. Fermi, Università di Pisa, Pisa, Italy 125Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, United States of America 126aLaboratorio de Instrumentacao e Fisica Experimental de Particulas - LIP, Lisboa, Portugal 126bFaculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal 126cDepartment of Physics, University of Coimbra, Coimbra, Portugal 126dCentro de Física Nuclear da Universidade de Lisboa, Lisboa, Portugal 126eDepartamento de Fisica, Universidade do Minho, Braga, Portugal 126fDepartamento de Fisica Teorica y del Cosmos and CAFPE, Universidad de Granada, Granada (Spain), Portugal 126gDep Fisica and CEFITEC of Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal 127Institute of Physics, Academy of Sciences of the Czech Republic, Praha, Czech Republic 128Czech Technical University in Prague, Praha, Czech Republic 129Faculty of Mathematics and Physics, Charles University in Prague, Praha, Czech Republic 130State Research Center Institute for High Energy Physics, Protvino, Russia 131Particle Physics Department, Rutherford Appleton Laboratory, Didcot, United Kingdom 132Ritsumeikan University, Kusatsu, Shiga, Japan 133aINFN Sezione di Roma, Roma, Italy 133bDipartimento di Fisica, Sapienza Università di Roma, Roma, Italy 134aINFN Sezione di Roma Tor Vergata, Roma, Italy 134bDipartimento di Fisica, Università di Roma Tor Vergata, Roma, Italy 135aINFN Sezione di Roma Tre, Roma, Italy 135bDipartimento di Matematica e Fisica, Università Roma Tre, Roma, Italy 136aFaculté des Sciences Ain Chock, Réseau Universitaire de Physique des Hautes Energies - Université Hassan II, Casablanca, Morocco 136bCentre National de l’Energie des Sciences Techniques Nucleaires, Rabat, Morocco 136cFaculté des Sciences Semlalia, Université Cadi Ayyad, LPHEA-Marrakech, Morocco 136dFaculté des Sciences, Université Mohamed Premier and LPTPM, Oujda, Morocco 136eFaculté des sciences, Université Mohammed V-Agdal, Rabat, Morocco 137DSM/IRFU (Institut de Recherches sur les Lois Fondamentales de l’Univers), CEA Saclay (Commissariat à l’Energie Atomique et aux Energies Alternatives), Gif-sur-Yvette, France 138Santa Cruz Institute for Particle Physics, University of California Santa Cruz, Santa Cruz, CA, United States of America 139Department of Physics, University of Washington, Seattle, WA, United States of America 140Department of Physics and Astronomy, University of Sheffield, Sheffield, United Kingdom 141Department of Physics, Shinshu University, Nagano, Japan 142Fachbereich Physik, Universität Siegen, Siegen, Germany 143Department of Physics, Simon Fraser University, Burnaby, BC, Canada 144SLAC National Accelerator Laboratory, Stanford, CA, United States of America 145aFaculty of Mathematics, Physics & Informatics, Comenius University, Bratislava, Slovak Republic 145bDepartment of Subnuclear Physics, Institute of Experimental Physics of the Slovak Academy of Sciences, Kosice, Slovak Republic 146aDepartment of Physics, University of Cape Town, Cape Town, South Africa 146bDepartment of Physics, University of Johannesburg, Johannesburg, South Africa 146cSchool of Physics, University of the Witwatersrand, Johannesburg, South Africa 147aDepartment of Physics, Stockholm University, Sweden 147bThe Oskar Klein Centre, Stockholm, Sweden 148Physics Department, Royal Institute of Technology, Stockholm, Sweden 149Departments of Physics & Astronomy and Chemistry, Stony Brook University, Stony Brook, NY, United States of America 150Department of Physics and Astronomy, University of Sussex, Brighton, United Kingdom 151School of Physics, University of Sydney, Sydney, Australia 152Institute of Physics, Academia Sinica, Taipei, Taiwan 153Department of Physics, Technion: Israel Institute of Technology, Haifa, Israel

121801-17 week ending PRL 114, 121801 (2015) PHYSICAL REVIEW LETTERS 27 MARCH 2015

154Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv, Israel 155Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, Greece 156International Center for Elementary Particle Physics and Department of Physics, The University of Tokyo, Tokyo, Japan 157Graduate School of Science and Technology, Tokyo Metropolitan University, Tokyo, Japan 158Department of Physics, Tokyo Institute of Technology, Tokyo, Japan 159Department of Physics, University of Toronto, Toronto, ON, Canada 160aTRIUMF, Vancouver, BC, Canada 160bDepartment of Physics and Astronomy, York University, Toronto, ON, Canada 161Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Japan 162Department of Physics and Astronomy, Tufts University, Medford, MA, United States of America 163Centro de Investigaciones, Universidad Antonio Narino, Bogota, Colombia 164Department of Physics and Astronomy, University of California Irvine, Irvine, CA, United States of America 165aINFN Gruppo Collegato di Udine, Sezione di Trieste, Udine, Italy 165bICTP, Trieste, Italy 165cDipartimento di Chimica, Fisica e Ambiente, Università di Udine, Udine, Italy 166Department of Physics, University of Illinois, Urbana, IL, United States of America 167Department of Physics and Astronomy, University of Uppsala, Uppsala, Sweden 168Instituto de Física Corpuscular (IFIC) and Departamento de Física Atómica, Molecular y Nuclear and Departamento de Ingeniería Electrónica and Instituto de Microelectrónica de Barcelona (IMB-CNM), University of Valencia and CSIC, Valencia, Spain 169Department of Physics, University of British Columbia, Vancouver, BC, Canada 170Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada 171Department of Physics, University of Warwick, Coventry, United Kingdom 172Waseda University, Tokyo, Japan 173Department of Particle Physics, The Weizmann Institute of Science, Rehovot, Israel 174Department of Physics, University of Wisconsin, Madison, WI, United States of America 175Fakultät für Physik und Astronomie, Julius-Maximilians-Universität, Würzburg, Germany 176Fachbereich C Physik, Bergische Universität Wuppertal, Wuppertal, Germany 177Department of Physics, Yale University, New Haven, CT, United States of America 178Yerevan Physics Institute, Yerevan, Armenia 179Centre de Calcul de l’Institut National de Physique Nucléaire et de Physique des Particules (IN2P3), Villeurbanne, France

aDeceased. bAlso at Department of Physics, King’s College London, London, United Kingdom. cAlso at Institute of Physics, Azerbaijan Academy of Sciences, Baku, Azerbaijan. dAlso at Novosibirsk State University, Novosibirsk, Russia. eAlso at TRIUMF, Vancouver, BC, Canada. fAlso at Department of Physics, California State University, Fresno CA, United States of America. gAlso at Department of Physics, University of Fribourg, Fribourg, Switzerland. hAlso at Tomsk State University, Tomsk, Russia. iAlso at CPPM, Aix-Marseille Université and CNRS/IN2P3, Marseille, France. jAlso at Università di Napoli Parthenope, Napoli, Italy. kAlso at Institute of Particle Physics (IPP), Canada. lAlso at Particle Physics Department, Rutherford Appleton Laboratory, Didcot, United Kingdom. mAlso at Department of Physics, St. Petersburg State Polytechnical University, St. Petersburg, Russia. nAlso at Louisiana Tech University, Ruston LA, United States of America. oAlso at Institucio Catalana de Recerca i Estudis Avancats, ICREA, Barcelona, Spain. pAlso at Department of Physics, National Tsing Hua University, Taiwan. qAlso at Department of Physics, The University of Texas at Austin, Austin TX, United States of America. rAlso at Institute of Theoretical Physics, Ilia State University, Tbilisi, Georgia. sAlso at CERN, Geneva, Switzerland. tAlso at Georgian Technical University (GTU), Tbilisi, Georgia. uAlso at Ochadai Academic Production, Ochanomizu University, Tokyo, Japan. vAlso at Manhattan College, New York, NY, United States of America. wAlso at Institute of Physics, Academia Sinica, Taipei, Taiwan. xAlso at LAL, Université Paris-Sud and CNRS/IN2P3, Orsay, France. yAlso at Academia Sinica Grid Computing, Institute of Physics, Academia Sinica, Taipei, Taiwan. zAlso at Laboratoire de Physique Nucléaire et de Hautes Energies, UPMC and Université Paris-Diderot and CNRS/IN2P3, Paris, France. aaAlso at Dipartimento di Fisica, Sapienza Università di Roma, Roma, Italy.

121801-18 week ending PRL 114, 121801 (2015) PHYSICAL REVIEW LETTERS 27 MARCH 2015

bbAlso at Moscow Institute of Physics and Technology State University, Dolgoprudny, Russia. ccAlso at Section de Physique, Université de Genève, Geneva, Switzerland. ddAlso at International School for Advanced Studies (SISSA), Trieste, Italy. eeAlso at Department of Physics and Astronomy, University of South Carolina, Columbia SC, United States of America. ffAlso at School of Physics and Engineering, Sun Yat-sen University, Guangzhou, China. ggAlso at Faculty of Physics, M.V.Lomonosov Moscow State University, Moscow, Russia. hhAlso at National Research Nuclear University MEPhI, Moscow, Russia. iiAlso at Department of Physics, Stanford University, Stanford CA, United States of America. jjAlso at Institute for Particle and Nuclear Physics, Wigner Research Centre for Physics, Budapest, Hungary. kkAlso at Department of Physics, Oxford University, Oxford, United Kingdom. llAlso at Department of Physics, The University of Michigan, Ann Arbor MI, United States of America. mmAlso at Discipline of Physics, University of KwaZulu-Natal, Durban, South Africa. nnAlso at University of Malaya, Department of Physics, Kuala Lumpur, Malaysia.

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